I made this same... or very close to this setup. I got 2 rubbermaid containers, and lined both insides of them with mylar. This reflects the light all around inside, and prevents light through seeping through the plastic -- so its not a glow box! Lol.
I put them ontop of eachother, and then I cut out a strip of plastic on top, and put a clear plastic top on to seal it up. I screwed 3 light sockets into this, and wired them all up, and put Y splitters on each of them. This allowed me to have 4 26w cool, and 2 46w warm, or I can switch it up. I think I might add or swith to a 150w HPS, or just add some more CFL's, who knows... The clear strip allows me to view inside the box without opening it, as well.
On the top compartment, I added 2 computer fans that suck air out, on different sides. Then, on the bottom compartment, I cut out and glued in a big 8" fan, that puts air in.
I put my thermometer where the tops of plants are, and it seems to read a constant 75-78.