IIRC, the docs for Trilian don't list the basses used. I play a 5-string Warwick Corvette with active electronics. There are time it's easier to get what I want by playing a real bass; there are other times, I'd prefer to use midi (so I can easily transpose and play in perfect time at consistent volume). :-)

In my perfect imaginary world, I'd like to be able to play a song w/ Trilian and at my discretion, come back and play parts with my bass, with it all sounding seamless. Is that realistic? If so, does anyone have an idea what samples I should use?

I know I can try them all, and tweak them and tweak my bass EQ, pup selection, etc... but if anyone could save me the hours of experimentation it might require, or just point me in the right direction, that would be awesome.