Spencer had a far better year than Elam. Spencer was rated the 10th best 3-4 OLB, Elam was rated the 51st best safety.
I think you're keeping the wrong one.
I'm not convinced that Mario Williams can be an effective strong-side LB in the 3-4. I'm even less convinced that his contract needs would be low enough to entice the Cowboys.
The McIntosh proposed signing is interesting though.
Not sure about Langford. He performed very badly vs the run this year. He does have some pass rush to his game though.