like n8magic, i have a pair of 60s, then upgraded to the 125s - i love both, but definitely prefer the 125s. as far as the differences between the 80s and 60s, i'd say its personal preference, i never wanted for anything when using my 60s, that's for damn sure, i was more than happy. the only time i ever noticed that i wanted more was after i listened to a friends pair of 125s, so you will not regret if you decide to go with the 60s, thats for sure.
as far as driving them from your pc, i can't comment on the 80s, but the 60s are fine on the pc output - the 125s are marginal at best, i just don't bother, if i'm listening from the pc, then i use the 60s. i would assume that the 80s fall somewhere between there, just fine if you're listening at lower levels, but if you want to jam out, they might be a lil too hard for your pc to drive, notice i said might there.
anyways, the point of my ramblings are that you will enjoy either set of cans you buy, you definitely won't regret either of them one bit.