I've posted pics of my TEC block installed in various threads on this forum. Not sure if I ever posted any with my complete system, I'll try to dig up some of my old pics. I'm planning a rebuild so I can fit the TEC block again, but I'm hoping to migrate to a new case that fits more of my radiators.
Re the TEC specs. Ebay TEC's typically name TEC's very simply, ie 12715 = 127 couples (127 couples means 15v as well), 15 amps, they'll also include a size, like 40mm. Then they trick you by saying 231w, but that is maximum power consumption, not Qcmax, ie the cooling power of the TEC, the Qc is actually about 130w. It is a false idea that you are buying a really powerful TEC when in fact it is just power consumption not heat transfer ability.
My 19940 is closer to its specs than the ebay TEC's, the problem is the spec sheet is extrapolated data rather than actual tested data. ie, they will take a single couple of N and P type semiconductors, test it's performance, and then extrapolate the data based on voltage, couple count etc, so in reality the data is quite optimistic. Customthermoelectrics data sheets are pretty good. My TEC is theoretically 669w of Qc, in reality it's not that good, but still just about the most powerful single TEC that can be bought. The power consumption of this puppy at Umax and Imax is actually greater than 960w, ie ~24v x 40a, so they aren't falsely listing the power consumption as though it is the cooling power (Qc) like the ebay TEC's do, otherwise it would sound even more outrageous.
Re ebay tecs, I typically compare them to customthermo data sheets, ie for 12715, I find the 15.4v 15a 127 couple TEC, and check its data, then derate it about 10-20% to get an idea of how it will perform.
you really need to avoid thinking about more amps = higher cooling ability though, that only really applies if you are stuck with 127 couples because you are limited to 15v, on the customthermo site you will see there are some high voltage low amp tecs that have fantastic possibilities and can be very very efficient