Are those dimensions in centimeters or inches? If that's in centimeters then that would make it a 50 gallon tank, so that 250 watts of halide would be grossly over the top - unless the light were raised high to reduce the energy penetration into the tank. I'm sure it could be made to work, even at the worst case, but that would take a LOT of CO2 and flow. If you're asking the question in the first place then that probably means you currently lack the skill to execute such a feat without the technical assistance of Tony Stark (Iron Man.)
On the other hand, if these dimensions are in inches then using a single bulb would not easily permit an even distribution across the length of the tank. A series of longer T5 tubes would be the way to go in this case.
Cheers,