Thanks for the question! It is usable with the Whisper but not the Dragonfly.
It will fit with MSR fuel bottles with threading. It should fit any fuel bottle they produce.
The new pump should work with the stove. Through the years, the only changes have been the braided metal fuel line (added in the 90's) and the shaker jet technology added later. The pump attachment has not changed. You will also get a new windscreen with the pump, and the new pump will improve the performance of the stove significantly.