If you want, you can get the 3212S lite-on and o/c to a 40x with Mt. Rainer support. Works perfectly and a lot of people I know have done it. I say this because the 32x would be a few less $$.
EDIT: The 32x model doesn't support PCAV out of the box, but when you make it a 40x, it does.
here is a link to another thread that explains exactly how I overclocked mine. The 32x W model can be overclokced to 48x I think, maybe even 52x,. The forum I gave you explains it all.