Ok, here is my suggestion for the bills.
QB- Levi Brown ( Who??) 4th string QB. Has the best arm of the 4, and has the most stable package of TAS, TAM, and TAD.
RB- Spiller, ( If you don't know, you will....Madden GOLD) ( Jackson #2)
Fb- Lynch ( Similar to Cowboys with Jones/Barber) ( This way, you can get all three RB's involved by going Dual RB, Jumbo backfield..etc. These are your playmakers, use them)
WR-1 Evans
WR-2 Hardy ( 6-6, Rocket catch potential)
WR-3 M. Easley ( 91 spd decent cat and cit) You will be tempted to use Roscoe Parrish here because of his 95 spd and 96 accl, but avoid temptation. HE will break your heart with his 48 CIT) He is strictly a gimmick play, bubble screen, or 9-route receiver. He is also useful for PR, but you have spiller...and once you use Spiller, you'll want the ball in his hands as much as possible)
TE- Shawn Nelson is a very useful weapon. He is only 70 OVR, but 83 speed and at 6'5", can also be used for ROcket catch potential at WR.
OL Not a lot to work with here unfortunately. Two decent young guards in LEvirte and WOod, but terrible tackles in Bell, Meredith and Green, and the center Hangartner is just a guy. DO whatever you want.
OK, Defense is where you must forget everything you see, and go strictly by what you know. Now, the Bills switched to a 3-4 defense this year, but their personel is WAY better set up for a 4-3.
So, at RDE put "LB" Aaron Maybin ( brings him from a 60 ovr to 77 ovr, 85 spd, 87 finess move)
At RDE, its up to you. If you want a run stuffer, go with Dwan Edwards, but I go with "LB" Aurthor Moats. ( Brings him from a 59 OVR to a 69....yuck..but he has 81 speed and decent finess and power move)
Then I put Marcus Stroud back at DT where he belongs along with Dwan Edwards. You could do a lot worse.
LB- This is ONE SLOW UNIT. There is no combination here to get excited about, so just go with your 3 best tacklers.....which are all 3 MLBS.
LOLB- Andra Davis
MLB- Paul Posluszny
ROLB- Kavika Mitchell
CB- McGee
CB- McKelvin
FS- Byrd
SS- Whitner
KR- Spiller
PR- Spiller/Parrish
Not the sexiest team at all, but if you get stuck with them in a franchise, you could do a lot worse in my opinion.