The only shame IMO is that it's soldered on fins, not skived...
Personaly I think 50mm is'nt
that wide. What barb/tube are you using as an inlet?. I would'nt use a threaded barb as they're so restrictive, I'd use 13mm Cu pipe(15 outer) matched to 13mm I/D silicone tubing. Then I'd work out the internal surface area of the 13mm circle and make my inlet 'channel' area slightly smaller than (or equal to) the pipes area. You would have to try and maintane(sp?) this 'area size' through the transition from circle/pipe to slit/channel to keep it optimised though...
I dont see a problem with the coldplate mounting at 3.5mm, it may take more than 4 bolt/screws to achieve 100PSI needed (112 IIRC) though
, as 3.5mm is'nt much thread depth. I'd thread them into the B/P only, not the poly top!, outside of the waterseal (O~ring?)...
Nice to see a TEC head here, I disagree with JD on this, I think they're more 'efficient' than phasechange. Phasechange is alot of work IMO. TEC's are such a small bit more than normal H2o, another PSU, a coldplate and some condensation proofing...
The only thing putting me off of a 220watt TEC is getting my paws on a PSU for it!, (13~15V, 30amps: continuous not max peak)...