calsnowskier
Sarcastic F-wad
(I assume 'expect' was meant to be 'except'. Not a rag, just explaining where I'm starting with my answer, and acknowledging that I make typos all the time as well.)
The Giants get the same pick no matter who he signs with - a first round supplemental pick. The difference is that the Sox don't lose their 1st round pick, which doesn't affect the Giants' pick.
Edit: the Giants don't get the other team's lost pick. That changed in the most recent CBA (before, they would have).
The Sox have their first rounder protected (#7), but have forfeited their #2 and #3 picks after signing Sandoval and Hanley.
The Giants currently pick #20 and #37.
QOs still on the market...
Scherzer
Santana
Shields
Cabrera
Cruz
Liriano
I think this is a complete list. Personally, I think the Giants should only look at Scherzer from this list. #20 (at worst) can be a good player.