My ring sizes are all between 10 and 12 myself, so I do share your frustration in finding rings.
Etsy is typically my choice for jewelry shopping these days; it can be a lot to search through, but there's usually going to be at least two or three crafters or designers who made something that suits your tastes.
For example - would this work?
http://www.etsy.com/listing/61200273/stackable-garnet-ringIf you've ever wanted larger rings, I also recommend
HardCandyGems; the stones are wonderful. I own one of her labradorite rings, which is very sturdy and comfortable. It's well worth the relatively small amount she charges for her work.
Etsy also has the benefits of offering a service (Alchemy) where you can request a custom piece from other people; you set the materials, the style, even the amount you want to pay, and people bid to take the job.