Heres a link to a few different designs from various gigs I've done.
http://gallery.mac.com/simonpugsley#100001
My catalyst is based on the XL 20u single rack - the UPS will move when I add image-pros - LCDs will move to an external box (not in the drawer)
I used to take care and build the XL Catalyst dual and single racks - the majority used to remain permanently cabled with 2 scan converters and a decent rear panel. Changes were made on a job per job basis.