FYI, Tom's is soon featuring both of these CPU's (along with 3 others) in an upcoming story, tested stock and overclocked. I can't play the spoiler, but if you can wait...
Other thoughts: Consider which socket path you want. In the US, I'm noticing boxed Deneb getting scarce. So that X4 965 may soon disappear. Priced less than the 750K... sounds like a good deal!
oh, BTW, Athlon II X4 640 is in that story too, so you'll get a good look at what L3 cache adds and when. Athlon II (Propus) is basically Phenom II (Deneb) minus the L3 cache. The Trinity-based 750K is quite a bit different, 2 Piledriver modules/4 cores.