if you trust him to stand up to his end, since he has a couple good referances... what harm is there in waiting? Both snakes are subadults, so they aren't breeders that you'd need to get through quarentine to breed this season right?
I'd let him feed and clean up after them until he got certified. You always have the DHL as a last chance option if you decide you REALLY have to have those snakes instead of a refund.
Maybe you should ask if you get any perks since you'll wait?