I built mine from melamine over the christmas holidays. Was going to buy one but they were waay too expensive. This one cost me under $100. Its got 5 spaces for tubs, tubs i use are cb70's. Use can use any tub smaller, as long as its same height. I used belly heat zigzaged from top to bottom(very easy). Temps stay perfect at 90-91 with a Herpstat. Humidiy is pretty good also.
Also for the wood, u can get it precut at HD or whatever and just screw it together, pretty simple if you are good with your hands. I can give you my measurements if you want.