That should work fine. The one place I would not cut any corners though is on a good proportional T-stat. I've built a couple of racks as well and I prefer a lidless slide out system. Either or will work and I have to say that in building mine I started with online plans and I am still perfecting the way I build my racks. It is an evolving process. After your first rack you will see some things you want to improve on and the process continues one rack at a time.

On a side note you would probably get better responce in the DIY or Caging forum areas.