uh oh
peltier is a power draining whore so watch out

you might need another PSU for the peltier...

i dont think your 450w can handle it
there are also PSU's specifically for peltiers that can be added to a working system

i really dont think its necessary at all to get a peltier unless you are doing hardcore overclocking

seriously, watercooling is good enough already for a hard push for OC
unless the Maze3 block he is selling you is a premodded from dangerden that has a pelt on it which i doubt so