yeah the aquaero6 is the gold standard. You can also use an external interface completely independent of the PC to control it. They also make QUADRO and OCTO "hubs" which behave much like controllers, only they are controlled via USB and software. They can both "target" a set temperature, but I'm not sure if they are technically PID or not. The aquaero can make virtual sensors (like deltaT over ambient) and then target a specific temperature on the virtual sensor.