Ok, choosing a bjt is an easy task, take the maximum frequency you want to operate at and multiply the amp stage gain and get a Ft high enough to do what you want. Do a parametric search for that Ft or higher and bob is your uncle. But what about non RF mosfets? There are like 20,000 mosfets on mouser even if i narrow that down to package type and power dissipation i am left with 300 transistor. So what are the search parameters that are going to narrow things down to something that may work for most of HF? I could buy 1 of everything and then build a test jig and see how each of them goes, but narrowing that list down to say 10 or so potential devices would help a lot here. So what are the most critical parameters that limit frequency of operation in a mosfet?