I'd always be happy with a 3-shear tup, especially from a breeder. It means he was good enough to keep and use twice, and probably means that some of his daughters have been retained and he's now to be sold or he'd be tupping his daughters. Whereas an unproven shearling tup might not leave good lambs.
Check his testicles, feet and mouth, and if all those are okay, he's probably a good 'un.
I'd also recommend Charollais for easy lambing and excellent fat lambs, btw.