...congratulations. Every crankset has a stated requirement for the length of the spindle, so you select the new crank first, than buy a new sealed unit in that length (or pretty close to it), in the proper width and threading for your BB shell. For yours, I think the BB shell is 68mm wide and threaded standard. So it should be readily available, once you you figure out the spindle length you need. If you install the cup thingies that hold the sealed cartridge in place using anti-seize, it makes it easier to remove next time around.