Very nice! With that TEC I'll bet you could hook it straight up to the 12v side of a molex connector and you'll be set. They say TEC's work with the most efficiency at half their rated voltage. So if your TEC is 24v rated, then give it 12 and leave it. It won't pull too much current (about 6 amps) and won't produce nearly as much heat, while also pulling the heat away more quickly than at full rated voltage. It won't pull as much, but as long as it's not being overwhelmed by the processor (it's obviously not lol) it'll run just as cool.
A side note: 24v @ 12a are absolute maximum values. The cooler the hot side is kept, the less current the TEC will draw. So you're probably not even going to pull the 6 amps, maybe a little less.