We did a similar tasting this summer with 6 people, as far as BCBS we ended up with Rare, Vanilla, 09 bomber, 2012 coffee and regular, bramble and cherry. We did all of the bombers blind and drank the regular 2012 first just to get a feel for the base.
We didn't experience a whole lot of palate fatigue, but even for 6 semi alcoholics, a bomber a piece was plenty. We ended up having a lot more beer left over than we thought, so we ended up doing a cuvee as well as made floats with vanilla ice cream after we tasted some more beers. I'd recommend adding 2-3 more people so you don't end up bastardizing bcbs like we did.
Although, floats and a cuvee isn't terrible if you're into that kind of thing.