, forgot to mention GeForce gtx 750ti.
Still, I am not worried about total power. Just noise and heat at the top of the case.
You should still be fine with 400W with GTX750ti.
One thing worth mentioning is that on my HTPCMi build, that has top mounted PSU with a hole, the noise from the PSU will be noticeble, in my case the X400 if i place my ear right next to the case hole i can hear some electrical buzz on the PSU, but at 1mt its inaudible to me, this sort of things are different on each persons hearing and tolerance. I can tell you also that in my past TJ08-E build, i had an Seasonic X660 (gold) with GTX480 and then GTX580 and then a GTX780, and i never heard my PSU, it usually was off on idle or barely spin up for a minute and then off for some time, even playing games i never really heard it, i had to stand up and take off the filter to see it spinning, as long as you dont get any coil or electrical noise that you can perceive, the seasonic imo are one of the best PSU in the market. That said... some users have reported a lot of coil whining on seasonic platinums, that i personally haven't experience any issues with mine.Corsair RM450
is also a decent option, should be semi passive most of the time. Kingwin LZP550
should be another good option, reviewed by SPCR and got the editors choice, Kingwin Lazer Platinum 550W Power Supply