Need Help on Metal Halide lights

[slipknot23]

I have a 75 gal tank can some one tell me witch one I can use? I wood like to use 2x70 HQI Metal Halide if I can but if I can not I will get 2x150 HQI Metal Halide. I have a pic of the ligths. Can some help me

 

[acrylic51]

What are you planning on keeping in the tank?? Personally I would opt for the 150's if they were my 2 choices, but if you see an upgrade in the future it might be worthwhile looking at the 250's instead