Hi Nick,
Great, I'm glad you've got it working on the '683!

You'd need to check microchip.com and use the product selector tool they have to find which PICs have the oscillator options you want and then cross reference that with the supported devices list for the compiler version you have.
If you find yourself in a position where you need to consider upgrading to PBP3 I wouldn't hesitate a second. The big difference is how the CONFIG bits are handled - and it's a big step forward IMO. Then you have the conditional compilation features and (since you're even on pre 2.50) you'll get support for 32bit variables when using PIC18 series devices and a couple of new commands.

PBP doesn't really know much about the hardware but obviously your device programmer needs to support the chip you're programming for - you need to check the list for your particular device programmer. I have a PICKit3, it's cheap and it works.

/Henrik.