Earlier, I was strong on MS carbon booms, but I would also like to recommend Wolfgang Lessacher's asymmetrical Duo Weed fins. In my opinion, these weedfins are the "kind" product for slalom and speed sailors. Great resistence to spinout and tons of windward capability. Also, one can run very small sizes and still get great lift.
However, if one has a focus on waves, I would highly recommend the True Ames Weed Wave. It's an older design "special order" fin, but I think that it's worth the manufacturing wait time. The 9.5" version works really well with 5.7-7.0 sail sizes in wave conditions, even with tons of heavy kelp. The weed shedding ramp is so small that its really notable, and it's quite a narrow chord lower aspect fin at the base. Very maneuverable and flexible overall.