hi lady A,
i hope this works out for you. you said that you think the breeders themselves may also be new to this...hopefully you can work together with them to educate them too.
point them in the direction of TICA's code of ethics & explain that you really wouldn't feel happy putting the little lad at risk & would rather wait until the recommended time to collect him, & for them to have him innoculated. they may charge you extra to cover the innoculations, but you would have had to pay that yourselves anyway
unfortunately many accidental litters of non-pedigree kittens are born & people sell them at 8 weeks or so. it seems to be the norm. i thought it was the norm until i got interested in pedigree cats & learnt how risky this age is to send kittens out into the world. people have let their un-neutered cats roam free for many years, but we are gradually educating ourselves on better routes of welfare for our feline friends.
these breeders may have grown up around these moggy litters & may not realise that the pedigree cat world is very different & there are proper ethics to follow. they have their cats registered with TICA by the sounds of it, so they seem to have good intentions & you felt comfortable meeting them & their cats.
don't give up hope, it may simply be that they don't realise & once you have pointed them in the direction of the code of ethics, it may turn out just fine, but please don't be tempted to take this kitten before 13 weeks old
best of luck & please do keep us posted!