If the Bills pass on a WR in R1, I think that your list looks about right. I'd probably drop Malcolm Kelly and add Jordy Nelson. Looking at R2, it gets no better. The first 8 teams are all in need of WR help to some degree and I'd expect them all to strongly consider one at their respective positions.
So yeah, I agree with you. If the Bills try to wait until pick 41 to get a WR in this draft, they're probably going to be **** out of luck. If they really want a quality WR prospect, they're either going to have to pick him with that first rounder or trade up from 41 into the early 20s, which will be pretty costly.