We can definitely do the "Fenris" ring in 18K White Gold for you. There is a slight charge of $75 for the customization/upgrade.
I wanted to point out that you originally asked for a 11mm white Australian south sea cultured pearl for your custom ring, whereas the "Fenris" ring we offer has an 8.5mm natural color Akoya Pearl from Japan; hence the pearl size is smaller than the larger 11mm we were originally going to custom make for you. Please also note that a custom pearl ring with an 11mm pearl is considerably more costly than a smaller size pearl that we already have in stock (because we have the ring in stock, we do not have to design a new ring style for you).
In addition, I wanted to familiarize you with the different pearl sizes. Fortunately, we have a section on our website that is called "Shop By Model" where we feature some pearl rings on actual models so you can get an idea of what pearl sizes look like on different women wearing them. Since I have been doing this for over two decades, I am intimately familiar with what the different pearl sizes look like and what sizes I think might be appropriate for a pearl engagement ring.
However, I wanted to bring this experience to you through this gallery so I have selected some pictures here for you to use as a benchmark for comparison:
Here is a 9.75mm natural color black Tahitian Pearl on a plain 18K White gold shank just so you can get an idea of sizing:
Here is a 10.5mm Tahitian pearl set on American Pearl's Eunice ring:
Here are two 12mm pearl set on two separate pearl rings. I think from seeing the 9.7mm pearl, the 10.5mm pearl and the 12mm pearls, you can get an idea of what you originally asked for in an "11mm pearl" and if its the right size for her and if your new thinking that you might want the "Fenris" ring with an 8.5mm pearl is right. Please see the pearls below:
Eddie
American Pearl
576 Fifth Avenue
New York, New York 10036
800-847-3275
Since 1950 - The World's Finest Pearls at Wholesale Prices
http://www.americanpearl.com
American Diamond
The Finest Quality Diamond Rings
http://www.americandiamond.com