Hey Joey,
First of all, buy used. You'll get two or three times the amp for the money that way.
Secondly, I'd say go with a head and cab rather than a combo because:
1) Combos are designed with compromises, and therefore have limitations in both volume and tone.
2) You can always pick and choose cabinets to fit the size/style of the gig. With a combo amp, you're pretty much stuck with what you've got.
As far as recommendations go, just use your ears. Bring your bass to some music stores and plug into everything you can find... THEN hit the used market!
Also, if you're gonna be playing with 2 guitards and a drummer, you'll want at least a solid 200 watts.
Mas power = bueno!