What PSU should I get given my PC specs?

prwler

Honorable
Jan 25, 2013
29
0
10,530
I'm looking into getting a new psu, but I'm not sure which to get. Here are my specs:

i5 200k
radeon 6870
8gb ram
2 hdd's (western digital caviar black 1TB and seagate barricuda 320gb)
asus cd drive
3 monitors (2 1920x1080 and 1 1440x900)

what's the minimum wattage of a new psu that I should get? I also want it to be a bit future proof, as I plan on overclocking eventually, getting a new gpu, etc. Thanks.