I think Bosh is a near max guy, but I wouldn't want to lock myself into an $80+ million contract at this stage in his career. With that said, I wouldn't rule out going after him either. He just barely turned 30 (so not that old) and has been to 4 strait finals - with 2 championships won. That's exactly the kind of experience that the Jazz need.
Favors, Bosh, Starting SF, Hayward (after they match his offer) and Exum makes for an interesting starting lineup down the road with Gobert, Kanter, Hood, Burks and Burke headlining a surprisingly strong bench. They'd still be a little weak defensively, but there's no doubt that it's a huge upgrade offensively over what they've put forth during the Corbin "era".
They'd certainly be more deep and dangerous with a guy like him on board. I'm not sure that he's worth the contract that he's likely to get if he leaves Miami, but I do think that he'd be a decent fit if they pursued him. IF they go after a max guy like that, they'd better be willing to fill out the roster and try to compete now. If they truly see Hayward as a SG, then they need to invest in a starting SF. Deng, Ariza, etc.