What does he think about getting 2 of them? Can one of them be smooth and one a different hair type? Try to encourage him to be more open with the type of pig and you might find more options. It would be so sad to think that you pass up a pig just because of hair type. I can understand wanting females (since I have 3) so if you can narrow it down to females and then be open to hair type you might have better luck.
My daughter is also extremely smart, gifted, talented..got rave reviews at our parent teacher conference, we were told she is an example to all. She really wanted a Nintendo Wii for Christmas but through my power of sugesstion I was able to talk her into wanting an ipod. I started showing her pictures of ipods and looking into what you can download to the ipod. Movies, tv shows, etc. Now she wants an ipod !!
(the wii is out of stock and cannot be bought anywhere) So maybe if you start looking at pics of piggies of all types and saying how cute and girly they look he might open his mind up. Also remember that although this is suposed to be "his guinea pig" you are the one who will be doing the bulk of the care for it and you do have a say in which pig(s) you get.
Good Luck!!