Oh OK so there's an option to have a square apeture built in instead of the octagonal one? Or do you mean a four sided frame of smaller stones to fit a square stone instead of an eight sided frame? Basically I mean is it just the apeture for the major stone or the entire shape of the frame you have the option to change?
If you go for a square stone like that in an eight sided frame (with the major stone set in a four sided bezel rather than in prongs) it it will look very Asiatic, I've seen square stones set where you would expect to see a round or octagonal one before many times in the jewellery of the middle east or India, it's quite striking and unusual, and will definitely make the ring stand out from the standard.
NB. You can have the bezel sit proud of the frame around it if you still want the major stone to stand out from the others...
