Upside down fork for 99 EC250

[revive]

Hi I am currently restoring my Gasgas 99 EC250 which has a conventional fork and is thinking of converting to an upside down fork.
Is there a specific model of Upside down fork that I can fit to my bike that doesn't need me to change my hub and break pumps?

 

[moto520]

Forks

Are you running the wp extreme forks?
I just bought a new 03 mc 250 with Ohlins (46mm).
Im selling the entire front end . I am putting on a 50 mm conventional extreme front end from a KTM .
performance@csinet.net