I've used champagne yeast (like EC-1118) before with good results. I wanted to try thie Cotê des Blancs to see if it would dry out just a little less. (It did... 0.998 vs 0.996 on avg with champagne yeast LOL)
As for the Chitosan and Kieselsol, not being a wine maker, I've never used the two (always associated the two with wine rather than beer). What would concern me with trying something new like that is if they are so effective that they'd counter the effects of the dry hopping I'm doing. Have you ever used the two with a dry-hopped beer?
I've always used Gelatin with good results in the past, that's why I plan to use it this time.
BTW, I noted that there was a special on unfiltered apple cider at the Ft Myer Commissary ($2.25 /gallon). I usually only do ciders a couple of times a year, but with that kind of price, I may have to adjust my plans LOL.
Biofine is a powdered preparation of purified isinglass (a type of collagen), isolated from the swim bladders of tropical fish. At the pH of beer, the collagen of Biofine has a positive charge which reacts with the negatively charged yeast cells and suspended solids, prompting flocculation. This accelerates the sedimentation process and produces a more compact, clearly delineated sedimentary layer at the bottom of the beer. The collagen binds with the yeast and other colloidal material in the beer, and is removed with the sediment. It does not remain in the beer. Biofine treatment makes clarifying beer quick and easy, significantly improves chill haze stability, and can also improve head retention in some beers.
0.5 ounces of powder makes enough solution for 100 gallons of beer. The solution is temperature sensitive, mix below 40F and store below 60F. There is a stabilized premixed product, Isinglass Liquid, requiring only a drop per 5 gallons, about 48 hours before bottling.