Lighting for 56gallon Column

Now to find a good affordable one =-\ I'd like atleast 2.5wpg lmk if you find anything.
 
Yeah I figured it's doing alright but it's pretty weak towards the bottom, I thought about just get MH but =-\ still hard to get a decent one, I also thought about just getting a 36inch CF cause the bulbs wouldn't be placed over the extra incches hanging off the edges =-\ **** my like of deep and tall tanks! (or I could just use two 30inch fixtures?)
 
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