how much are u looking to OC?
if u jsut wanna OC a few Mhz or what not i dont think the SP97 is necessary...its $50 or so right?
you could just go with the Zalman CNPS 7000A-AlCu (not sure if it fits ur Asus tho)
I got two of these Zalman's and they are awesome. I would recommend these over anything else unless you are doing a serious OC then go for watercooling.