There are many great PFDs now on the market that will work for trapeze sailing. Generally you want one with flexible foam, decent room around the arms for mobility and a high cut for the trap harness. Generally, a PFD designed specifically for sailing will have a slightly larger back panel, so is less thick than a kayaking one. However, the best one is the one that fits you!!! Give yourself at least an hour, go to a shop with great selection and try on as many as you can with your trapeze harness sitting down, standing and kneeling. I have many customers who have bought my least expensive PFD because it works best for them. Just because you get 20 people on this or another forum or in a parking lot tell you that you have to have brand x, model y, doesn't mean it is the best one for you.

I have used lately both a Salus Abacus (www.salusmarine.com) and a Gul Rodeo. Both work well for me (I don't ever notice its on while on the water)

Scott