Realistically, you only have two options:
CH products:
http://www.chproducts.com/retail/y_fsyusb.html
or Saitek:
http://www.saitek.com/uk/prod/yoke.htm
Those are new of course, and I'm not mentioning the ridiculously high end stuff (Cirrus etc) which are
really expensive.
Second hand, you'd best monitor someplace like bidorbuy.co.za if you want local, or ebay if you can manage the international shipping and associated hassles. Locally, I don't know how many second hand USB yokes you'll find - most owners will still be using them! Good luck.