It is important to select your power supply based in what other hardware you will add to your case, because if OP want to add a video card, then he will need a bigger power supply... By the way, a 1600W is just too much power, i have an 800W supply and with that my electricity bill goes to sky from $15/month to $40/month.
If you have a computer that draws only 250W with its components nothing will change on your power bill if you put a 400W or a 1800W power supply, the 1800Wis the maximum it can offer (in theory) not the amount it consumes continuously.
Anyhow, OP, cheapen for a few $ on a power supply and you might regret it tenfolds.