Keeper prospects

I think these are my keeper options:

Jeff Garcia, QB TB 4th round
Trent Edwards, QB Buf 8th round
Sage Rosenfels, QB Hou 8th round
Adrian Peterson, RB Min 2nd round
Marion Barber, RB Dal 3rd round (already kept once)
DeAngelo Williams, RB Car 3rd round
DeShaun Foster, RB SF 6th round
Fred Jackson, RB Buf 8th round
Darren Sproles, RB SD 8th round
TJ Houshmanzadeh, WR Cin 1st round (already kept once)
Braylon Edwards, WR Cle 5th round (already kept once)
Jabar Gaffney, WR NE 8th round
Shaun McDonald, WR Det 8th round
Chris Henry, WR none, 10th round
Owen Daniels, TE Hou 8th round
Nate Kaeding, PK SD 8th round
Stephen Gostkowski, PK NE 15th round
Tenessee Titans, TM Ten 8th round
Minnesota Vikings, TM Min 8th round

(Free agents are treated as though they'd been drafted in the 10th round, hence all of the 8th rounders here. What do other leagues do? The Vikings were actually my 10th round pick.)

I see Peterson and Barber as huge bargains so I will keep them barring any major injuries before the draft. I think I would keep Trent Edwards or Jeff Garcia as the third keeper (remember the value of QBs in this league). I'd have considered Braylon Edwards and TJ Houshmanzadeh and DeAngelo Williams if they were a couple of rounds later. Longer shots are Jabar Gaffney, who has been getting lots of good publicity, and Gostkowski.