Could well be worth trying the Marshall sim as well, just keep the presence, treble and bass down and keep the gain down to keep the sound clean. An open-backed cabinet may help as well. A clean Marshall running at low volume can have a very warm, almost bell-like tone.

Quite a lot of jazz guitarists use solid state amps, the Roland Jazz Chorus being an obvious example, also Polytones which are really bass amps and also amps aimed originally at electro-acoustics. The main thing for the Joe Pass "cocktail jazz" kind of tone is an absolutely clean amp with slightly reduced treble and bass so there's no "twang" and no bass thump either. Basically you're looking for the kind of tone an acoustic arch-top puts puts out only louder with very even response across the instrument's range.

For a Reinhardt "electric" sound I'd suggest the Randall Tweed - there's quite a bit of break-up going on on Reinhardt's later recordings where he had a pickup fitted (though some of that might be due to overloading the recording equipment used).