I think drlava's design is nice, for a general purpose PID controller. We're all going to use these TEC drivers for the same thing though; cooling a laser. The conditions will be fairly similar across all users for us however, which opens up the possibility of a more specialised solution.
As far as I can tell you need one PIDC120/150 for each laser as well, unless you mount them in the same block (which typically isn't possible with red diodes if you use for example a die4drive).