Short frame bikes ['99-'01] had the padded top & external fuel pump. Long frame bikes ['02+] had the smooth top & internal fuel pump.
AFAIK, the tanks are all same length/fitment, just the frame in front of the tank mount was extended slightly [approx. 1"?], but you might want to consult a copy of Guzziology or contact MI for confirmation.
If you've already got an external pump tank, it would be a minor chore to convert to the internal pump, but it eliminates the hot-start vapor lock problem. If you already have an internal pump tank, you won't want to convert to an external fuel pump, because you'll be creating problems for yourself.
Don't be so sure about the info....... My bike has the external pump w/pad on top of tank and it is listed as a 2003 Sport model.