Jim,
Since you said you were interested in suggestions for Spice models, so here's two:
SA612/SA602. There are models around, but I have no way of knowing how good they are.
BF904R. This strange dual-gate MOSFET is NLA, but was the secret sauce in some interesting RF front-ends because of its ability to run very high gain or attenuation (+-70dB in one example I'm aware of) with amazing IP3. A model would help in finding something that can reproduce this performance. Yes, I'm aware of Phil's GaAs/SiGe cascode combination...
Just a thought, in case it tickles your fancy.