Nathan, two years ago I went thru what you are going thru. I had 30 inch long tank, and wanted to get at least 60 watts of light, with good reflectors. But, I also didn't want to pay AH Supply's prices. I studied the AHS website and decided I could design a reflector as good as theirs, made of wood, with aluminized mylar over it, for three 20 watt bulbs. So, I did so. The problem was that, first of all, the T8 20 watt bulbs were actually 17 watt bulbs. Then, finding aluminized mylar, thick enough to be workable, at a low price, in less than 100 foot lengths, was beyond my abilities. So, at someone's suggestion I found a "space blanket", made of aluminized mylar, cheap. I got it and patted myself on the back.
The end result of this was about three weeks time in my well equipped shop, having fun, but with a result of a 51 watt fixture, with a wrinkled mylar reflector, that immediately started dulling. I kept working at it. Then I found that 30 inch T8 bulbs are very hard to find, especially with high Kelvin ratings, and those that were available were around $6 each, not the $2 I expected.
To stop the tear jerker, I ended up spending just about the cost of AH Supply kits for the lights and reflector, but only had 51 watts, with a poor, but well shaped reflector. After just a few weeks of use I realized how limiting the light was, and how the reflector was deteriorating still further, so I bought a pair of 55 watt AHS kits, thus spending roughly double what I would have spent by going with their kits from the beginning.
But, I'm happy - I had a good time designing and making the fixture, and I now have good lighting. Somewhere in all of that should be a lesson for you.