Hey, Jim - since "flocs sediment faster than individual cells" as Mark said, I doubt that you will find a quick sedimenting, but low flocculant yeast strain. I have found that some low flocculant yeasts can be coaxed into sedimenting by chilling the finished beer, so there are ways to get brighter beer quicker even though you are using an otherwise low flocculant strain. And there is always fining....