If it's USB, chances are it is supported by X-Plane. If so, it will have virtually unlimited configurability.
As an example: I use RealFlight r/c flight simulator. There isn't a Mac counterpart, so I run it in XP SP3 Boot Camp. That all aside, it comes with a USB flight controller, which is basically a 8 or 9 channel transmitter for r/c aircraft.
Back to the Mac and X-Plane:
I plugged it in, started up X-Plane, made a couple of calibration steps and set some switches and knobs the way I like (for gear & flap, for instance) and off I went. (X-Plane version 9). X-Plane has the most accurate flight models. Period. Its basic control engine is used in their FAA certified IFR flight trainer. There's a large user support base where you can download/purchase custom aircrafts and more.
If you do go with X-Plane, here's an amazing add on: a moving map display on your iPhone/iPod Touch using "Sky Charts". It covers the entire US with sectionals, FAA airport information (including: IFR Approach & Departure charts!). The iPhone links over LAN (wireless) to X-Plane and receives virtual GPS signals from the X-Plane aircraft in flight. Very slick - watch your flight progress during flight or get un-lost 😉 . I believe Sky Charts has plans for tracking path and possibly for the IFR plates.