I finished this project a few months back, just never got any pics up till now.
These craft carts from Target work great. I put three of them connected together, for a total of 21 containers...they each have their own lid and are escape proof...
I built a frame around it with 1x2's, it still wobbles a bit--if I do another one I will just put a sheet of plywood on the back to give it some stability...and I left the 1x2's long, I am going to put a few storage shelfs on top of it...
I am the ultimate fan of Reflectix insulation, so this rack got the full treatment...a lot of work but well worth it considering the heat is only one 18' length of Big Apple Herp's heat rope, running behind the containers...it uses 50 watts...and the temps stay good...even with the room at 74F I still get a 88-90 hot spot on the back end of each container...
So untill my babies get here, I am using it as temporary housing for my smaller boas and pythons whenever I clean their cages...(that is why there is a big ball python at the top...)