If you pull out your current BB you will find the 3 bits of info you will need, diameter (68?) and length(102?). there is also a difference in the BB threads, english or italian. your cranks are easier, just make sure it will mate to your new BB, isis, square,....
With all that said, this may be a good time to abandon the cassette style BB and go for an outboard cup style BB and solid axle crank setup. probably more expensive but nicer imo.
2010 Kestrel RT900SL, 800k carbon, chorus/record, speedplay, zonda
1997 Trek ZX6000, 6061w/manitou spyder, xt/xtr, time atac