6' light for 8' tank??????

On an 8' long tank will a 6' t5 light fixture work or should i get two 4' fixtures and put them side by side. I am unsure if the the light will fill in 1 foot on each side of the tank?

Here is the fixture I am thinking of getting at the end of my cycle.

72 Inch 8x39 Watt AquaticLife T5 HO Light Fixture w/ 6 Lunar LEDs

 

I'd do 4 MH's or 2 x 4 ft T5's.

 

Yeah I'd do the 2-48" T5's much easier to pick up and move if needed. One person can do it. My old 72" fixture was pretty heavy for just me and I can pick up some pretty heavy stuff..

 

Thanks I figured I would be told that since it is more money for two 4' lights than a 6' light. I can hear it now Hey honey I need more money for the fish tank;D

 

LOL. But they are right. 2 feet shorter just wouldn't cut it. Maybe a foot, but 2 is a lot.
And yeah, like gras said, the big fixtures are heavy. My 72" that I just got is right around the 75 pound mark.