I think that he will be easier to acquire than Woodley as I doubt Woodley will see free agency.
Furthermore, signing a player like Asomugha gives us more flexibility at the top of the draft, which I really like. This way if Quinn and Peterson are gone, you aren't forced to reach on a player and can make a solid deal to trade back.
My personnel pipe dream, sign Asomugha, draft Patrick Peterson, and then trade DRC for mid to late first and take Anthony Castonzo/Von Miller/Aldon Smith. This would give us four physical corners in Asomugha, Peterson, Toler and M Adams and allow us to address either the offensive tackle position or the pass rush as well.