For anyone who is a bit handy with DIY projects...
If you decide you want to upgrade your lighting, you could always go with ODNO (do a quick search on ODNO) lighting.
The cost for nearly 4wpg (48w x 4 bulbs =192w) on my 55g (not including the the canopy) was:
(2) 4x32 electronic ballasts - ~$60
(

regular end caps ~$16
(4) 32w, T-8, 6500K Phillips lamps ~$16
Total ~$92
By simply removing two of the bulbs I can drop the wattage to ~2wpg. Replacement bulbs are dirt cheap.
For more flexibility, you could go with three 2x32w ballasts and have the ability to simulate a dusk to dawn type lighting schedule.