I currently have 10 racks from RBI and I love them. The racks come fully assembled and are reasonably price with a very fast turnaround time. Also Rich's customer service is second to none. He will help you with any problem you may have and is great for answering any question you may have.
I am going to say that depending on the size of your collection.... I like animal plastics for a smaller collection.. I am going to try to go to the ars rack with the built in bowl holders it is freaking killer, and for 30 slots in a 41qt tub it is as cheap as the other racks.....
I use Chesapeake bay ball python racks. Hes got 6 qt, 32 qt, and 41 qt and a divider for the 32 qt tubs too. They come with heat tape and tubs. Could not ask for better quality along with nicer people. They are awesome. Just picked up three new racks from them today. Thanks Rich and Brandi http://cbballpythons.com/