PSU for a tiny rig

So I'm building into the Lian Li TU100 ( and wasn't sure where to go with the PSU.


Power: First off its going to be built with an I5 4670k and GTX 670. I'd like to leave a little overhead for overclocking if I can, and I was thinking in the range of 350-400W. Do you think I can get away with less or do I need more?

I don't think it matters too much for power, but there will be no optical drive, a 2.5" HDD and SSD, and a closed loop cooler.


Size: Second, I can't quite figure out what form factor I need to go with for the PSU for it to fit in the case. From what I have managed to find it seems to take "SFX power supplies up to 170 mm" (acording to, but I honestly have no idea what that means.


Any help would be much appreciated and thanks in advance.

I would get 550w or 600w psu. They cost like 10 dollars more and u have more room for things :D