Hey, guys! Thanks for all the info and sorry for the delay in getting back to you. I wanted to make sure I had checked out my new gear first.
I played around with a few DI boxes, some of which featured some gain and distortion parameters. They all worked great (including the Sansamp) as DI boxes, but I found the gain to be a bit lacking in tonal quality. The box I finally decided on is the Rusty Box by Tronographic
The Rusty Box is a DI pedal with a distortion sound so saturated and so much like a tube pre I'm really amazed that I'm listening to solid state.
I've read that the Rusty Box is based on the pre-amp in a Traynor head. I've read the specs on the Traynor bass amps and now I have a new object of gear lust - the Traynor YBA200-2
Of course, even if I had one, I wouldn't take it on the road and would use my Rusty Box with my GK or Fender Bassman.
In any case, if anyone is looking for a nice, aggressive bass growl in a low-maintence solution, I'd recommend getting the Rusty Box.
I use it directly in the board at home (I live in an urban apartment, so bass amps would be antagonistic to neighbors) and I can get a good rough idea of what something is going to sound like before I go back in the studio.
Customer service was pretty good from Tronographics too.
Anyway, drop a line if you have any questions.
Thanks again for all the information you've given me!