
As said, your puppies, you call the tune even if you need puppy buyers! I'd have thought if you explained the situation to these people they'd have understood how difficult it would be having to wait for them to sweep in and make their choice!! Frankly I'd be choosing a suitable puppy for them, based on what you know of their life-style and the temperament of an ideal puppy for them, and send them photos. If they don't like, they can buy elsewhere. I did just that with recommended friends of a fellow-breeder living in Switzerland. The people was more than content to take my advice. I flew out with him, heart in mouth that they'd still like him because once outside the country, I couldn't bring him back with me!!! They did and all was fine.
Again to protect the rest of your buyers, I'd tell them just that - you can't be expected to hang around on one out of 6 people wanting these puppies. And as said, to some extent warning bells would be ringing re these people, for me too. I had somebody who started making lots of demands on me to the point that finally I'd had enough, told her I'd decided to keep the puppy (which I did). She was upset of course, but I didn't regret not selling him to her at all.