Nice job, funny rack comments!
I like several things about your solution, the two things I like most being the nice look, and the slide-out being for each component individually (am I seein that correctly?). Using this strategy, the torque on the back brackets is a lot less. No problems with 26" extension of a 50lb device say (i.e. 108ft-lbs of torque)? Can you give any more detail on exactly what parts you used?