The enclosure looks great. There is one suggestion I would add though. Instead of using the clamp on your lamps, wrap the cord around what they are currently clamped to. That way they hang verticle and there is no chance that they fall off. If you do this, you can take your clamps off the lamps as well.
On the clamp lamps, get clamps from the local hardware store to secure them. I have a half dozen C-clamps I use to secure my bearded dragons' heat lamps whenever I have to use the clamps (aka, whenever I can't otherwise hang them from a stand or even just set them on top of a lid). Keeps them from falling off, and gives me peace of mind. I'm not sure wrapping the cord around the beam, like ekm suggested, is an especially safe way to do things? It can be done and would give you some stability, but I doubt the cords are designed for the lamps to be hung from them...
Other than that, nice table! It looks very well done. Any shots of the inside for us?
I hung my lamps with the little hanging ring that both your lamps have. Just got some cheap chain and S-hooks to hang them exactly where I want, and I can adjust them easily. Secure, no pressure on the cord, and cheap!