Hmm.. I'll answer you'r first two questions first:
A. I dunno, it looks OK and its not too costy, but for almost same price you could get a nice thermaltake big typhoon or a zalman CNPS 7700-Cu or the CNPS9500 if you got enough cash [and room in you'r case, lol]
B. Dunno if its gonna fit a northbridge, but in that site of yours theres another one that says flat out that this will:
About the built in graphic core.... i'm not sure what you mean, like.. an on-board Video card? If thats what you mean just look @ you'r computer rear side [the back side.. where you connect thing] if you have a VGA connection on you'r mobo than the answer is yes... if you ment something else then i'm not sure, sorry.
Hope this helps somewhat....good luck.