I have a HVLP sprayer (Turbine Products, Stage 4).  By all accounts you want a stage 4 or stage 5 turbine.  I’m using a gravity fed gun (also from Turbine Products). 

I have not sprayed poly.  Oil based poly, I use wipe on.  Done right, I think it is nicer than sprayed. 

My attitude about equipment is this:  If I am teaching myself how to use equipment, then I want to buy the best quality equipment that I can afford.  If I buy a cheap gun and my results are poor, then I don’t know if I am at fault, or if the cheap gun is at fault. 

Once I master the process, I will sometimes use cheaper grades if I don’t think it will degrade the quality. 

Cheap tools either do not work well, or do not last long.  If you know it works well, and you are wiling to deal with the shorter life cycle, then use the cheaper tool.

Turbine Product’s gun and turbine have proven to be very good.  It would be on my recommended list.  They sell direct and I think they are located in Connecticut.

The key, I have found, is getting the right viscosity.  A Ford cup is used to measure viscosity in paint, and is a very useful extra.  Also, you should always filter the paint as you are filling the cup.  Disposable filters are available from Amazon.  Also, clear disposable mixing cups are available.

If you get a gravity feed gun, you are going to want to get a spray gun stand.  It holds it stationary so you can fill the cup with paint.

I got the mixing cups, filters, and stand from TCP on Amazon.  All good stuff, all affordable.

You don't need a turbine for clear poly.  People have been spraying poly out of Critters.  Obviously, don't use a Critter.  Since you've done autobody work, most rules apply except note that WB flashes off really quick - so watch out for dry spray too.  You usually can get retarders for more of the higher end stuff, which helps levelling.  Don't think there is one for varathane. 

Best of luck, and have fun.

*All said turbines are nicer when you get into this - less overspray.  But you do have to fight the heat more there :/


edit: Q-You say you've done auto painting.  I assume it means you're familiar with spray guns on that end - and not somehow referring to bomb cans? 

My own view is kinda like Packard -- I am not skilled enough to get good results with cheap equipment.   
So I got a Fuji 5 stage and use GF High Performance poly.

But having said that, with the above equipment anyways, I find spraying waterbased poly is so easy to get nice results that perhaps woodferret is right that lesser equipment could readily be used.

Lots of good YouTube videos out there.   In particular, don't put your gun too far away from the workpiece.   Practise spraying water before you move to spraying poly.

One tip.  If you are a beginner, it is easier to get good results when spraying horizontal surfaces.  You don’t have to worry about runs and drips, and a generous coat of paint will benefit from gravity assisting with leveling.

Vertical surfaces are more difficult. Too much paint and you get drips.  Too little and you get orange peel. Cabinets can be painted in sections so that you are always spraying on horizontal surfaces.

Slower drying finishes level better as a rule.  Mask off surfaces that have already been shot.  Overspray will dust onto the other surfaces leaving a very rough texture.

For paint, I find the extremely slow drying and even slower curing Benjamin Moore Advance line of paints are very easy to get a quality finish from.  But slow with 16 hour recoat times.  A nice result though. Imperfections I see on the finished result are invariably the result of poor preparation, not from the painting process itself.

The only issue I found was getting the paint to the right viscosity.  A Ford Cup is effective in measuring viscosity.  It is basically a small cup with a hole at the bottom.  You fill the cup with paint and time it to empty.  Once you establish the ideal viscosity, spraying becomes easy.

I have a stage 4 turbine.  I have to thin Advance.  I’ve been told that if I had a stage 5 turbine I would be able to shoot Advance undiluted.  That would have been a blessing.  It takes time to accurately thin the paint to the right viscosity.

I paid about $10.00 for my Ford cup; i see them advertised for as low as $5.00.

https://www.google.com/search?q=ford%20cup&ie=utf-8&oe=utf-8&client=firefox-b-1-m

The original Ford cups were made from machined aluminum, and calibrated versions cost over $500.00 each.  You don’t need that kind of precision.  Any of the ones with a long handle will work fine.  The short handle ones will be problematic.

https://www.thomassci.com/Equipment/Viscometers/_/FORD-VISCOSITY-CUPS

Thanks all for your feedback.

Have been going down the turbine rabbit hole. Not convinced I need a 5 stage, and have been looking at the Fuji Semi Pro 2.

Everyone makes this sound stupid simple. Thinking my wife may be able to utilize it as well for some of her furniture projects.

Since furniture refinishing is being thrown in, I'll defer to Ray of Sunlight.  She's got a comparison of Fuji Q4 vs a few of the standalones like Homeright and Wagner. 

It'll at least give you a comparison on how well each class atomizes and how finnicky they are to viscosity of paint.  You _CAN_ do okay with 2 stage as the classic Earlex is basically that.  Shoots GF paints and the polys.  Heck, even Homeright can put paint on walls. 

I've got a MiniMite 4.  Strong enough to push some primer and lacquers.  When you really need a 5-stage, you're very straddling the line into airless territory (at least for trim/cabinets).  The swaying factor for me of 5-stage vs airless is cleanup.  It's immeasurably easier to clean the HVLPs especially if you use a PPS style system.  But volume is silly small unless you use a pressure pot, and then you've lost that cleaning advantage.

Thanks all. Am still shopping, but am set in getting a HVLP turbine set up.

A question for you all, my first project will likely be garage cabinets out of baltic birch. Would you spray prior to breaking down sheets? or once fully assembled?

Easier to spray piecemeal as Packard says.  Or oversized breakdown parts if your paint has edge puddling issues.  8x4 is too painful to spray as you need to overreach across the 4ft span (the other dir is too long and you'll very likely lose your wet edge). 

If your assembly marrs the surface, spray after.  Make the back slot-in/removable.  Or you can go the route of prefinishing the inside, but learn to mask cabinet openings for spraying the outside.  3M handmasker is your friend.

My own view is kinda like Packard -- I am not skilled enough to get good results with cheap equipment.   
So I got a Fuji 5 stage and use GF High Performance poly.

But having said that, with the above equipment anyways, I find spraying waterbased poly is so easy to get nice results that perhaps woodferret is right that lesser equipment could readily be used.

Lots of good YouTube videos out there.   In particular, don't put your gun too far away from the workpiece.   Practise spraying water before you move to spraying poly.

I spray with a Fuji HVLP MiniMite4 and the GF High Performance sprays well out of my fuji.