The guides I was thinking of come on flipper door slides. They have a roller to protect the door as you're pulling it out. They probably could be repurposed to use as regular guides but I've never tried it.
Just in case anybody is going to do it, here are some options for protection.
Here is a KV roller trolly that I found. (Never used one so not sure of the required spacing.) Plus it's ugly.. Here is the bumper I was talking about.
Figuring out how to do something you have never done is what makes a good challenge.
