I think it is Barron who will decide.
He cannot stay healthy, he has what are obviously some chronic issues.
The Rams can't pay big numbers for a player who misses so much time. But.....at the right price perhaps. But that price is probably in the $3mil range. Doesn't sound like a lot in today's market, but $3 mil for playing football for a year is an awful lot of money. More than he's going to make doing anything else.
As for Suh. I really don't know. He's still playing at a very high level. He stays healthy. And if the Rams don't feel they can pay him, I'm sure that there's a few teams that would. I think Suh will have to give some what of a home town discount in order to stay. I'd say he'd have to accept maybe a 3 year $35 mil deal that really is a 2 year deal worth about $23 or $24 million. The man has made a huge amount of money; I suspect he'd love to play his final years in a city he prefers and on a team that has Super Bowl possibilities.
So if it came down to the Rams only being able to keep one or the other (and I'm not at all sure that is a real option), then for me it's Suh hands down.