If the style is on the website, you can go that route. Otherwise, I've had luck emailing Betty with precisely what I want (model #, color, last, size) to see if it is something Carmina carries in their stores and can ship to me.
One thought is to use Bick 4 or the AE bourbon polish. I use saphir for all my shoes, but would not for a very special color like bourbon. I have a similarly complex color from Carmina and have not used anything but Bick 4 and wax thus far. I know that I will eventually have to use the mid brown polish on them, but I'm holding out for as long as I can.
Have you seen the double leather sole on shell strands previously? I do not want to go all style police on you, but I'm having a tough time visualizing a balmoral with a double leather sole. That said, Strands are more casual than a medallion cap toe might be for other makers, so it's not the craziest idea I've heard. So, if you've seen the finished result before and like it, then go for it.