I'm telling you from personal experience that the Biostar is a great board, and explained why that person thinks Biostar is "eh".
With a 64-bit OS, if you are downloading Win7 RC, it has two different versions. Just make sure you download the 64-bit version.
Overclocking is milking more performance out of your processor, and that combination I have been recommending the whole time is great for overclocking. With your stock cooler, you won't be able to overclock TOO much, but you can at least get to 3.2ghz easily and not worry about temperatures.
EDIT: Also, as for editing your posts. If you just posted something, the general rule of thumb is to not post right after that one if no one has answered. Just edit the first of those two posts.