They way I look at it is that the Bills have a lot of holes to fill - OT, OG, C, DE, OLB, TE, SS. That being said, I think that drafting Pettigrew @ 11 makes the most sense because he is the best player available at a position of need. The only other player from this list I could see them taking at 11 is Curry, but that is a pipedream at best.
I totally understand your point about the need for a pass rusher, but none of the DEs impress me enough to justify using the #11 on them.