I don't plan to over-clock so you think I'd be fine with the stock Heatsink? Yes

Are there any issue with the some of the old software and going 64 bit?
(i.e., Office 2003, games) If they are 32-bit based you won't have a problem.

Also, my Anti-virus sweet (Trend Micro)is expiring this week, thinking about changing. Any good suggestions? Anyone going the free route? Dump that crap, get MS Security Essentials, free download