According to
realhardtechx, NOX's units are made by CWT who also make many of Corsair's units. However, NOX's units seem to only have 2 year warranty, which doesn't put them in a very good light IMO, and the NX series lack efficiency certification as well (which may also mean they lack Active PFC...). I would stay away from NOX.
CX500 should handle that hardware fine, but I would honestly prefer some other unit with longer warranty and better quality caps. Where are you buying from? Maximum budget?