I used the cheapest slides I could find blum euro knock offs been working fine for me,

Cabinents heights well you should be able to access the top shelf with little or no  need for a ladder etc

"The only thing I would add, is that I would use full-extension guides and get them as deep as your cabinets will allow.
Also, since this is a custom set-up, you are not locked into any specific height with them. Set the working height to you, rather than some accepted standard of kitchen cabinets. This way you can match the height of things like your tablesaw for an out-feed unit or your assembly area at a better height for your body."

This is what I am planning now. I want to put my RAS and SCMS on the same wall with their work surface the same height so they can share it and the fence system. The RAS is currently at 39.5 inches on the factory leg set. My SCMS is mounted on a mobile MS stand with extensions and the work surface is at 37 inches. Right now my plan is to build the three cabinets at 39 inches and have two adjustable platforms between them so the RAS and SCMS will be at the same height. I also want to have dust collection for both so I'm thinking about how I will accomplish that. The three cabinets will have drawer storage and under each saw a scrap bin for offcuts I think.

I would like to build my Kreg Foreman into the benchtop too. But I am not a huge pockethole fan so I think it's better to leave it as a portable unit I drag out when I need it. I thought about leaving the RAS on it's original stand but I would lose some storage space if I do. I keep going back and forth on how to put it all together.

Personal preference, but I actually like the epoxy roller slides better.  Yes, you miss out on the last couple inches of each drawer, but I like the lower friction. 

I'd love to have the Foreman built in, but my cabinet setup is really shallow.  The deck on the foreman machine might stick out further than you like.

The lower friction and free movement are nice, but the only way I would do that is to use the longest ones that will fit and move the back of the drawer up so that nothing is covered up or blocked in by the shorter travel they have. The sides need to go the full length of the guides, but the back doesn't have to be all of the way back there.

I'd like to do a nice job, though, to advertise to my wife what I'm capable of.

#1 Rule, never point out your mistakes. Most will never notice them.