Wow, that's some serious coinage. I noticed that you've used a lot of off-the-shelf parts. If you started from scratch again would you have some parts like waterblocks and radiators custom made and larger so they are fewer in number? Maybe fewer but larger pumps? Maybe go with copper pipe and use soldered joints? With so many rotary fittings, are you worried about failures? Did you consider phase change before deciding on TECs?
Sorry for the wall of questions. Very interested.