With a tube mic, you'd probably be better off with a solid state preamp...
One more thought... Unless you get into the high-end (over $1000) tube preamps, you'll probably encounter what is refered to as 'starved plate' tube... Which means the tubes operate at really low voltages like 9-12 volts, instead of up to 300 volts that the higher end stuff operates at. These lower voltages really won't add anything sonically 'good' to your sound...
The above paragraph is what I have read by several users on several forums... I did however, last week, order a lower end tube pre to test with... After those tests, I'd be able to give you 'real world' scenerios...
Bottom line: You'd probably be better off with a good, clean solid state preamp unless you spent over $1000 for a tube pre...
Just my .02 worth...