Adding the names of proven all-pros next to unproven draft picks is a bit misleading.
While I think OT is clearly the Bills' greatest need (who needs a WR if your QB is on his back all the time), I'd have to take Fitzgerald from your list (he currently ranks fourth all-time in league history in receiving yards per game for a career).
The probability of Floyd being that good is a BIG, BIG, BIG if, however...