you want lots of low wattage peltiers, this spreads the load out and improves efficiency (As much as one can using a pelt any way) All so to keep Amperage reasonable wire them in such a way as to use 120V, and do a direct rectifier circuit so you don't have to mess around with low voltage high amperage ( this will net you a tad bit of efficiency as one less conversion loss ), Low wattage pelts should be cheaper too so make it with two hot sides with all the cold sides on your chiller block, that will all so give capacity control as you simply switch on the second bank if you need more cooling!

Pick up 2 snap disk thermostat set for 60C or 70C=off for both the hot side of the peltiers and the rectifier, this will give you some safety preferably manual reset and of course a fuse. All ways keep in mind with pelts ther is all ways a risk of thermal runaway and can resualt in a fire! All so make sure all wires you use have an insulation rating of or better then 90C