Sorry if this answer isn't useful being something of a 'you're asking the wrong question' approach but here goes...
If you've got capital do you need a cofounder or could you look instead for an employee. If they turn out to be as good as you might hope they can then take more responsibility as the company grows and earn (additional) shares at that point. If they don't work out you've got a far simpler problem to deal with. More likely perhaps is they work out but aren't neccesarily interested/capable of growing into the person they need to be as the company grows. If expectations are set now you can still grow the company above them.
Best of luck with whatever you do.