If not in the right place it can be moved but it was a general off topic...

Can someone bring me up to speed on modern power supply differences? I haven't had to buy one in years so I haven't been following all the little details.... seeing everything from "new Active PFC supplies wont work with modified sinewave UPS's" to PSU's apparently needing to be Haswell ready since apparently normal ones are not (and i'm not sure why that would be), to perhaps other brand new things that I don't even know about yet.

I'm not looking for direct answers as much as "who has the best explain-it-all articles and most reliable reviews". Could you point me to your favorites or/and the best knowledge sources?

FWIW i'm having I assume the PSU start to go out (random crashes its never had before, no software changes, and its about 5yr old) on a main desktop PC (phenom 2 hexcore thuban with a 550 ti and four HD's/two optical) which i cant have go offline for long because it's the school PC, money is tight because.. well... school... but i'm trying to both avoid the class of PSU that actually is bad for hardware (poor ripple, I at least know about ripple, let alone overrated power and lacking full protection circuitry) while preferably being usable by a newer system when I finally have a chance to upgrade. I have an older modified sinewave UPS i'd rather not also pay to replace.

Power is real cheap like 8-9c/kwh so efficiency doesn't matter much - 80plus is probably good enough - even though I often leave it on 24/7 (a bad habit I need to break esp with a thuban). But a future board may have issues below 20% load, if the idle watts on newer systems stays that low, so I didn't want to buy too large.