Good news! A totally new prototype is a rare chance Contessa, I don't want to put any pressure and stress on you (ok maybe just a little:greengrin

but you have a rare chance to do it YOUR way. I know you loove your stone and I agree it is gorgeous. Don't settle for anything less than what you already have. If you need breath down their neck to make it right and the way you like it. I know many goldsmiths want the easy way out and start marketing the styles they already have in stock by saying "popular choice" and "trust me I know what I'm doing". Ugh! the goldsmith isn't the one who is going to wear it and he doesn't know what you want unless you tell him the specifics clearly and insist.
Think of it as building your own house and you want big bathrooms and stone walls. If the contractor starts saying that small bathrooms and regular walls are the popular choice and he knows what he is doing, will you give in and let him do whatever he likes? You are the one who will live in the house, kwim?
Good luck with everything!