Looks like the company that put out the following PDF:

http://home.earthlink.net/~wksands/nonlin.pdf

has spice models. I suppose you have to pay for them, though. I'm
surprised a Google search didn't turn up any free models. How accurate
do they need to be? You can bulid your own, certainly...you can use
the BJT model and add the package parasitic inductances, resistances,
and capacitances, and probably get decent correspondence with the way
real parts perform. I have a book about building Spice semiconductor
models, but haven't done any of that for a long time and never was into
it deeply enough to think I'm good at it.

www.duncanamps.com has quite a bit of spice stuff, including some
transistor models and links (some broken by now) to manufacturers'
spice stuff.

Cheers,
Tom