XLR Industries, is the only one that pops into my head. Manners offers a thumb hole stock(T5) which may be worth looking at as well. I've had an XLR, and spent a bit of time with a Manners T5. They are both excellent stocks.
Be prepared to wait and pay dearly for the stock though. The XLR will run about $750, and the Manners starts at just under $600.
Andrew