I bought some 8" ones from Halcyon
(scroll to the bottom of the page). They knit surprisingly well--very easy and easy on the hands. They're made by Clover.
The only thing I don't like about them is that they are plastic, but since dpns are killing my hands, I just have to get over myself
There are limited sizes on these: 4, 6, 8, and 10. But adjusting tension to compensate shouldn't be a problem.