Before you buy and start building, do your research. The less money you have to spend, the more it makes sense to spend it in the right direction the first time. If you couldnt afford it the first time, how will you be able to afford to do it again? Shop around and be patient. Ill bet you find a t5 fixture that will fit your tank in days if you look hard enough. And the price will be right. Or if you want to go MH, they are all over the place