Jimmy G is a better quarterback than Sam and a better fit. Jimmy G is an upgrade at quarterback over what Wilson was likely to be this year.
Sam might make more sense because we're probably going to take another partial swing at quarterback before next offseason as Zach insurance. A 25-year old former top-5 pick is the type of swing you want to make. Zach is still the guy going into next year, but you can't put all your eggs in that basket next year. Either you get a mid-round QB and hope you get lucky, or get a veteran who can potentially start if Wilson goes down or struggles. It's kind of like the Becton situation entering this year.
I'm not sure what other quarterbacks would make sense. Flacco and White are better than most of the other potential options most likely.