Ok. I spent a lot of time diving into the peltier cooling forums, in particular the PC overclocking community before building my cooler.
I went with a 12v system so that the parts were relatively inexpensive, but it still cost about $150 to build. The most expensive individual parts being the 2 40mm heatsinks.
2 TEC-12715 chips, each sandwiched between a pc heat sink (cooler master hyper 212) and a 40mm water block. Glycol mix (I used RV water treatment) is held in a medium sized cooler, and circulates through the 2 water blocks in series, and then dumps back into the cooler.
Electrically the system runs off a 30A 12V power supply. A 12v bus runs an inkbird temperature controller, pump and the heat sink fans.
A second 12v feed goes to a DROK controllable bucker and the variable voltage output goes to the TECs in parallel.
The Inkbird temperature controller can shut off the DROK in case the glycol reservoir drops below freezing (ha!). There is also a 2nd thermometer at the output of the water blocks to ensure that they don't freeze.
I made a small case for it, the only noise is the fans for the heat sinks and the power supply.
The second picture is of an older prototype, which used a smaller cooler. It was unable to cool a fermenter due to the volume discrepancy.