i believe if you ask that in the lighting filtration and equipment forum, they might be able to help a little more. also, there is a DIY section. there is an acrylic thread that a few acrylic people could help you out some too. i have no personal experience with acrylic, but acrylic does bow. (it doesnt look good or safe, but it is usually ok)
i am not trying to get you off this thread, but if you repost in one of those sections, you might get a faster response.
good luck by the way. (you can post some build pictures and get a thread going if you want.)