An NF2 motherboard, or AMD XPseries CPU has a Socket A pinout. You can still get Socket A CPUs in the Sempron, Thoroughbred or Barton varieties, but they are becoming hard to find.
Newegg.com still has some, but many shops don't carry Socket A anymore as the new chips with new sockets are taking their place.
Just beware there are also Socket 754 Sempron CPUs that will not fit on that board.