In April of 2000, I was supposed to direct the pit orchestra for a musical and one of the songs called for a swing sound, so I decided to rent a double bass for that piece. I tried to Engelhardt M1s, at two different stores. The difference in sound between the two was astonishing, and came down to the setup. Let that be a caveat to anyone buying a double bass: Setup matters a lot.
The bass came strung with Thomastiks, which I pulled off and replaced with Pirastro Obligatos. The difference in sound is stunning, especially playing arco. Before I put these strings on, I was planning on buying a second bass to use exclusively for classical and solo playing and reserve this one for jazz/rock playing. With the Obligatos, I feel that I can let this wait a bit longer (and perhaps spend a bit more on the new bass).
I play with a german bow of unknown manufacture which will likely be retired at some point over the summer. I've pulled the crutch stop off the tailpiece (but kept it handy should I want to use it) and now keep a pair of rock stops handy as that's a more viable solution when playing seated. The black hole rock stop is clearly the best solution when playing on a slippery surface (especially marble church floors), but its strength is also its weakness. It's impossible to adjust the position of the black hole if the bass has its endpin in the stop.
I have a Realist pickup installed on the bass. It has no volume if I run it straight into an amp. It's even a weak signal going into my Mackie with the gain and volume cranked. It's passable running through my MDB-1 switchbox/preamp/di, but I'll probably want to get a preamp to boost the signal. Perhaps one of the ones that Bob Gollihur sells.
My other accessories are a Reunion Blues quiver for my bow and a Gaines wheel which helps immeasurably with transportation of my bass given my lack of car ownership.