urgh, lost my first post.
cpu and cooling isn't necessarily your biggest limiter when it comes to overclocking - your mobo is. chipset coolers are a great way to extend the life of your cpu. the high-riser sets are the best on this page, but simple heatsinks will work too. hope you got a good mobo, else you're screwed for OCing.
this. a hard drive is a hard drive, unless it's a 10k or an ssd.
xigmatek makes an excellent cooler. i'm pretty sure it should fit - i don't work with amd usually since the performance tradeoff isn't worth the monetary difference. i have one of these (lapped) on my e8400 and i got past 4ghz with ease. you might want to get an aftermarket fan, though - the ones that come with it are decent but not super-powered. if you're already ordering from petra's, nab a yate loon oversize (38mm thick) fan, and use pliers to cut some of the excess plastic away so that it still works with the xigmatek mounting system. it does wonders for your cooling temps. i mean, come on - a 120mm fan that puts out over a hundred CFM, and it's thicker so it's got more force to get air through the fins...and it's only like 6 bucks? sign me up! i bought nine when i ordered from there last time. petra's sells psu and fan dampeners, too, for cheaper than anywhere else. worth looking into.