IMO get a good quality fixed length carbon paddle and have a length that is a compromise in length between surfing and flat water.. About 6-8" overhead.
Brands like Naish, Starboard, Fanatic, Coreban and Hobie all have good paddles these days and brands like Kialoa, KeNalu, QuickBlade and Werner are other good options.
IMO get a blade size that's about 8" in width max.. and choose a skinny shaft over a thick one.. Your local sup shop should be able to help you decide.
If I had to choose one paddle to recommend out of the hundreds out there to choose from it would be the Kialoa Methane..