I have said this before and if I was the GM this would be my plan:
Take the KC first and trade it for cousins now and give him the big contract and extension.
You can give them Tyrod too or a mid round pick if the first is not enough. That KC pick is going to be in the high 20s anyway and there are to many bad teams in the league. If you give up that first, we still would have our first and 4 other picks in the first 3 rounds. We would be in great shape now and come April.
Just like ever year the draft class gets way over blown and the QBs are nowhere near as good as they say. If you trade for him now you only need to use the 1 pick to get your qb for the future. If we wait until the draft, it will cost a kings ransom to move up. You also then have to hope the team with the top picks dont need a qb for themselves. Lets not forget you are asking the Bills to then also identify which QB is good. Cousins has already proven himself in this league and he can help you now and later. If Cousins gets to FA hes going to go to SF. Make the move now and maybe we can win something with this Defense this season. Just because this type of thing doesnt happen, doesnt mean it shouldnt.