Quemazon,
Check out this website.

http://www.optronicsinc.com/competition.htm

I have tried both the QH-7CC and QH-8CC, 7 is chrome plated metal, 8 is a sturdy plastic. Otherwise similar and both work fine. Just depends on whether you want a chrome look or a black look. I have not found them locally, but Optronics will sell them to you if you give them a call. Either costs only about 15 for a PAIR, and both use MR16 lamps. They come with 50W lamps, but I put in either a 35W Solux or the 20W draw/35W light Phillips energy saver. To me these lamps make it hard to justify trying to design your own housing. They are fairly small, inexpensive and come with a mounting bolt. You just have to make or buy a simple clamp of some sort to attach them to.
Regards,
Raymond