There is a whole series of CM cases under the Elite name. But the XFX Pro 550W is the same size as the Extreme Power Plus 500w so it will fit.
If you want a PSU with detachable cables then the Antec HCG-520M that I linked uses the same internal design as the XFX, but is modular. It is slightly larger, at 160mm deep vs 140mm but it should fit depending on the case you have.