I also just started building computers myself, but I did some research and took alot of feedback before choosing this fan, though alot of the named ones are on here as well, these are the main sites I use for HS comparison, along with personal owners, ofc you have to compare where the person is to their temps, if they lapped their hs's, what TMI (Thermal Paste/greese) Your using etc. There are alot of factors that can change how much you get out of each Heatsink.
Anyways, Heres the sites I browse:
Has both Heatsink reviews and TMI Reviews, who would have thought that there are 2 nice cheap TMI's better than AS5? (And Made of better material for Direct Pipe HS's)
The 2nd site is www.frostytech.com
They have both intel and amd and overall heatsink comparisons. Some very nice testing goes into the mix.
I ended up picking up some OCZ Freeze TMI along with the Xigmatek HDT-S1283 Based on the amazing reviews everywhere, not only that, it comes with an excellent fan and is an easy install. (Though you will need to purchase TMI as it doesn't come with any). You be the judge on what your case can fit/handle though =). I'll post a review on my specs of this HS when I get it up and tweaking.