SOS Metal Halide

[alfredshouse]

Hoping that some of you pros out there can help me out. I am new to this reef tank hobby. Ive had fresh water fish for many years though. I have a 160gallon tank with a Fluval FX5 canister with an inline heater. About 100lbs of live rock and I just added 100lbs of base rock. No skimmer yet and Im going to add a #4 Koraline this weekend. I want to add a Metal Halide light. I just dont want to spend $$$$$$$$$$$ if I dont have to. So my question is can I just go to a hydroponics store and buy a light and ballast there. I was thinking 2x 175watt at14K. Is this realistic? Please advise!!!