help me to choose light and tank

[CaptNemo]

Hello everyone,
I should be writing my essay but i got to ask this quesstion and get it off of my mind. My 20H tank is a bit too small, i would like to upgrade it. if you have to choose between two tank, which one would you pick

oceanic 37 gallons (24"L x18.5w x 21h) vs oceanic 40 gallon Hex (30"L x 18.5w x 21h) dont' have to take into acount of the cost between them

which one is better when it come to choosing light for it?

i was thinking of putting a 70W MH with two 24" T5 on the 37 gallon (i can't do this light combo on 40Hex becuase of the tank dimension). would that be good enough, right now i just going to keep zoos and other lps or should i just upgrade the light to a 150W with 14K bulbs?

is it better to have a lower watt MH with some T5 or a larger watt MH without any T5. i am just afraid that the larger watts MH would be just too hot.

anyway, advise, suggestions are all welcome.

thanks

[tk1360]

being that they are so close to volume I am not sure. Hex tanks kind of rub me the wrong way and require a specific location where they look good. Also I like the lighting you mentioned for the 37 gal. the 70 mh and the t5s would definitely be nice. With that combo you could initiate a rising setting sun cycle versus the 150 w/o t5s. Regardless what you pick as a fellow essay shirker I will be following along.

P.S. reefcentral is my newfound procrastination outlet. Its great, before I was stuck cleaning things here I can do "tank related research". lol. Back to MY paper.