is there that much difference for bass? what are the advantages/disadvantages for each?
A solid state amp will be able to behave more linearly, but I don't think that the nonlinearity introduced by the tubes are more suited for guitar than bass.The choice isn't as straight forward as for guitar amps: the attractive voicing that makes vacuum tubes work so well for guitar doesn't fall in the register of most basses, but some like distortion.
The only additional limiting factor at low frequencies in a tube amp (vs solid state) would be the frequency response of the output transformer. This can be easily overcome by using a properly spec'ed OT. The frequency response of the Partridge transformer in the classic Hiwatt DR103 is around 4Hz - 100KHz (-3dB), according to:Tube heads can be ridiculously heavy for the power, while solid state amp are generally lighter. Some like the grind of the tubes, but I greatly prefer the tight bottom of solid state.
Another option if you are going down that road is a rack mount tube pre and a lightweight SS power amp (eg. QSC PLX series). Plenty of nice rack mount tube (or tube sounding) preamps available - Alembic F1-X, Demeter VTBP201S, Tech 21 Sansamp RBI, Fender TBP1, BBE BMAX-T etcawesome thanks so much everyone. you've been much help. so i think i'm gunna go with a ss amp with a tube pre. I cant spend too much so could you give me some specific models that would be good? max of $900 for head and tube pre...