Again, if LEDs are outside your budget you can always use 4 T5s from someplace like FishNeedIt. You'll have 2 T5s across the span of the tank. It'll be WAY cheaper starting out and you'll have a whole lot more plant options. It won't be high light, but it'll still be a big improvement. Large tanks just cost a lot to light. Heck, I spent around $50 just to light up my 5.5 gallon planted tank.
You can still try out one of those 20-30 watt LED daylight floodlights from eBay. It would take 3-4 to do the whole tank but trying one just to see how well the plants right under it respond won't be expensive. You can easily hang them with a fern stand from Lowe's or Home Depot. Cheapest option on earth for LEDs. If you want to see them on a planted tank just look up my build thread.