Help on picking out a fan / hs

Yes it'll fit that CPU because it is a LGA775 socket, and that HSF is a LGA775 cooler it'll work. Just make sure you have good thermal paste and your ready to go.
 
Why don't you just measure the clearance between your CPU and the side pannel? If you don't want to remove the current HSF, measure the distance between the HSF and the side panel, then add the height of the HSF 😛.

From the images I see on NewEgg, you might have to remove that side panel air duct.