Buy one of the beers, fill up your hydrometer tube and let it degas for a few days and then take a FG reading..you can back into attenuation with the ingredient list you have.
Using wlp001 or 002 would probably be just fine. If the recipe has a lot of unfermentable sugars use 001 or if it doesn't and you are looking for some body use 002.
If you post the recipe I can be more helpful..plus I'd love to see it.
Kegged and serving - American Wheat, Daves Porter, Outkast Kolsch, Nectar of Nuggets
Bottled: French Canadian Breakfast Stout, Edworts Apfelwein, Westminster Wit, Put that in your stout and smoke it
Fermenting: Apfelwein, Flanders Red, Skeeter Pee, Heady Topper attempt #1, Kumquat Berliner Weiss, Sabraton Accident Stout, Nelson RyePA
Upcoming: Session IPA, Yeti eqsue stout, Dark English Mild, ESB, CDA, Row 2 Hill 56, Zombiedust, Hoppy Amber, Geuze, 100% Brett Golden Ale