I agree with rgr4475, I've tried CF, VHO, T5s, I've had the best experience's with T5, you can get two 36" for even coverage, though make sure they will fit properly.
They are bright, cheaper than CF and the bulbs last two years.
I would personally not go any other way. For a fresh water tank, the reflectors are not too critical, so a "standard" kit will be fine. If you were going marine then it would be more important to invest in a lamp with individual reflectors for each bulb.