Looks awesome so far, I only have a couple questions about the design:

How thick is the base between the pelts and water (both sides)? IIRC, 3/8" is about optimal for a plain copper plate, so maybe have a thicker base for the cold side and obviously thinner on the hot side.

That brings me to my next question, the height/thickness/overall contact of the fins. The current design looks really free flowing, but I don't see enough of the cold dispersing through the loop. Machining and materials cost are a concern, but you might want to (somewhat) follow Swiftech's GTX and especially MCW6500 designs and reduce the height past the inlet/outlet, or angle the inlet down. Just a thought there from someone who's taken approximately 0% of the thermal/fluid dynamics classes you have.

And just to clarify for some other people, the purpose of this isn't to get subzero (even subambient) temps (at load at least ) but to effectively cut away some of the heat load on the actual CPU loop. Like Naekuh said, if he has 240 watts of heat, 180 watts of (theoretical) cooling from pelts would give him a CPU loop that only needs to dissipate 60 watts.