This will have to be kinda quick, as I gotta get back to work (and it's Monday, too!)
I'm running a Gigabyte GA-8KNXP-rev2, and couldn't be happier. You can get a nice little OC with it (at least as good as most other mobos) and the board is LOADED with features. Like 3 RAIDs (two SATA plus one IDE), eight USB-2 and three firewire ports. etc, etc.
On the other hand if you want the easest MAX OC, do get the Asus and be prepaired to modify (as in solder) the voltage regulator.
NOW FORGET THE ABOVE!
Get a piece of paper and draw two columns
1) First thing check prices on 3.2G (for stock speed or min OC) vs 2.8G (for serious OCing) CPUs
2) In your "stock" column add the price of nice DDR 400 RAM.
NOW TOTAL YOUR "STOCK" PRICE
3) in your OC column add:
a) The price of DDR 566 RAM
b) The price of a CPU and Northbridge water cooling setup. (unless youre already deaf)
c) The price of extra case fans and a modded or high-end case.
d) The price of anything I've forgotten to mention, but others may.
NOW TOTAL YOUR "SERIOUS OVERCLOCKING" COLUMN.
Overclocking can be fun, but it can cost a LOT these days, too.
Oh, and on the question of Northwoods vs Prescot, if you don't overclock too much go for the Prescot in RETAIL BOX form.