Hi
AP2,
If I understood you correctly, you plan on connecting 4 fans to your Aquaero? If so, and if those fans are not some server cooling monsters (38 mm Deltas or similar), you should have no problems connecting them to Aquaero. I have 6 120 mm Yate Loons and 3 140 mm Noiseblockers on my Aquaero and the temperatures are reasonable.
I am not sure you can even buy Poweradjust any more, I only see Poweradjust 2 in the Aqua computer shop, but if you're not planning to connect anything else you don't need one.
Kind regards,
Boris.