Does the Enthoo Primo provide monitoring of the CPU temperature as a basis of thermal control?
Such features (possible, for the $230 price-tag) would imply the controller's internal USB connection to the motherboard.
PWMs vary their own power requirements based on input from the PWM signal cable. They can be powered directly from the PSU. 3-pin fans, which are controlled by varying voltage under 12V on each channel, are the key reason that would make a fan-controller even necessary.
You might want to look at the Aquaero 5 LT for about $80 at either FrozenCPU or Sidewinder. There are other similar controllers like the T-Balancer products. These all allow USB connection to the mobo, monitoring of CPU temperature without need of applying a sensor wire, and no need for a front-panel switch or display. Of course, you can probably buy a 5.25" plate assembly for the Aquaero. Or just spend the $200 for that particular model.
If you don't want to shell out the approximately $80 to buy devices in the Aquaero 5 LT class, there is an NZXT Sentry for maybe $30 which allows each fan to be controlled using different corresponding thermal sensor wires, which you must place on (or "in") the processor, chipset heatsink or other component.