the 120mm is awesome. Low decibals, nice CFM at max movement, thats a definite one to go for. The 80mm fan is about average....should push about an average amount of air and have an average amount of noise to it. You could do better with that fan, and are LED's in the fan a necessity to you? Also see if you can't find a ball-bearing type 80mm fan instead of sleave bearing. And as for that 92mm fan with bracket, I'm not entirely sure how those brackets are supposed to be placed. I read a couple reviews and some people had it for their cpu and some said they had it for their chipsets so I honestly don't know how that works but I don't think it fits into the category of a 'normal' 92mm fan. If you want something exotic try this:
=) even that thing is a little weird to me. I personally plan on buying a little blower fan like this one:
to put on as the intake at the rear of my PC. Most will say thats stupid to have a rear intake, but the blower will blow perfectly into my coolermaster jet which also utilizes blower technology so it'll be pointing towards the rear...blowerfan blowing into a bigger blower fan =). That 120mm that you linked I think I'm gonna use for a blowhole at the top of my case. put that thing up there as an exhaust. I have a spare 80mm vantec tornado..dont know if I want to use it cause its sooooo damn loud unless I get a fan controller.