I am buying something this weekend sight un-seen! LOL seriously I am.
When it comes to animals like snakes you can easily tell what stock you are purchasing by knowing the breeder and what his animals look like. Its actually extremely common to buy sight unseen although not a "rule" of course and many people take pictures beforehand. But not always.
You can always ask Boa if he is willing to meet you for a look at them, and if you want them, purchase them but let him know you may want to turn them down if they aren't exactly what you are looking for.
Good luck. And its GOOD to be sceptical and paranoid when purchasing anything but you can normally easily tell if someone is shady or not.