Ok people have had issues with some vendors where their stock ended up thawing and re-freezing in transit, which made for some real gnarly feeders later, but I know both of those sellers and that wouldn't be a problem.
Maybe try transitioning to rabbits, if you can get them in the correct weight for your boa. They're tougher, I've never had one destroyed and that's even with my retics hitting them like the fist of an angry god.