Alright, now I'm researching the Traynor. Unfortunately, there's no nearby spot to check it out. Sounds nice, though. I've always wanted a tube amp, and a vintagey amp fits my vintagey music taste...
If you pair the Traynor with something like 4x10s or a 1x12 or 1x15 you aren't going to get the kind of volume you are looking for. A 2x15s or 8x10s would be ideal and should support you in ANY band situation. I used a 2x10 and 1x15 stack (not a good idea) but could hear myself quite easily over my crazy buff drummer and two all-tube guitar heads with 4x12s. With my 2x15's cab now, I would be screaming over them. Ask how many people on here gig with an Ampeg V4B head, it's only 100w and people gig on it with good results...that's HALF the wattage of the Traynor.
But if you feel like it's STILL not enough volume, take the amp to a good tech and get some KT88's put in. Trust me, I'd rather have to mic my cab and sound GOOD than be loud and sound cruddy. Tone is a YMMV, IMHO, IME and all that jazz...but I've noticed that every tube bass head I like has one thing in common...6550 or KT88 power tubes. But my original suggestion still stands...go get an Ampeg SVT if you can, Traynor should be option B.