I'm running my 600@850 right now with a nice watercooling setup.
No problems. Under full load it hits 90-95F. Not at all hot for that much over-spec. I broke the dips on the board, so I can't try higher yet. I am going to fix it and go higher myself.
My advice, due to power constaints, go with a watercooler. You can usually plug the waterpump into a 110 outlet, leaving your psu to power the system and not the peltier. It also allows you to run this at room temp, not subzero and risk condensation.
I haven't tried a peltier myself, so this is a one-sided opinion. Just my .02.