Looking for new lighting for my 59g

[magnosis]

I currently have a 48" Hagen 2x54W T5HO, but I would like a little more light (~3wpg) in my planted tank.

[edit] why I want a little more light is to help some of my plants to grow more into a carpet than to grow high (what I suspect is common for lower light environment, the plant seeks up to find more light) for instance I have a type of grass that gets very long (6-8in) whereas on a lot of pictures I see, this same plant keeps short and denser with >= 2.5wpg.

My options are:
a) keep this light, add another of the same type (this may be too much)
b) sell / exchange it for a 3- or 4-tubes ballast

My budget is a little tight to go with LEDs at the moment, though I'm willing to consider it.  Would be nice if the ballast had a night mode as long as this doesn't prohibit the amount of light I can get during the day (e.g., a 4-tubes ballast with a timer, that turns 3 tubes on during daytime, or 1 during night time)

Is there a particular / model brand that you would recommend (or, stay away from) ? 

Also if you have such a lighting system you want to get rid of, please PM me

Thanks in advance.