Okay, here's what you can do with Obi-Wan's hunt for Fett to separate it from Kamino. Perhaps the Jedi analysis droids determine the dart to be Mandalorian in origin, and you can construct dialogue somewhere (radio plays, audiobooks, manipulating the film's own dialogue) that informs Kenobi of a bounty hunter named Fett who wears the armor of the Mandalorians. How you go about Obi-Wan directly locating Fett is up to you.

Replacing some of the Kamino Prime Minister's dialogue in the cloning facilities can be easy enough if you can keep that dialogue in cutaways to the clones. If you don't see him on the screen, you needn't worry about matching his lip movements. It comes down to the voice matching consistently. It might be necessary to replace all his dialogue to achieve this if it is that crucial to your edit.

-NJM