I had picked out quite a few NFETs that I thought would be good candidates for this project: IRFP150, IRFP250, IRFP350, IRFP460, etc.

After reviewing Kerry Wong's video about linear FETs I went back through my list of candidate NFETs and culled out most of them. Nearly all of them did not specify a SOA under DC operating conditions...big red flag! I then went back to DIgikey and LCSC to see if there were any that would satisfy our SOA of 100V @2A. 

I found these: 

 SUG80050E (Still the best one) 

 FCH76N60NF (OK and I have a simulation model)

 IPZA60R045P7 (can't get the sim to run with this spice model) 

 IXTH60N20L2 (expensive and no model) 

 IXFH56N30X3 (ditto) MS170N15IDC0 (Chinese, but specs look OK. Needs derating. No model.) 

 NVHL055N60S5F (no model) 

 RU1Z200Q (Chinese.)

Without a SPICE model it is difficult to tell if it will work in the circuit. Therefore all I can do is list them as potential substitutions for the one we eventually pick, which right now looks like the SUG80050E.