These guys would probably have a collet nut for a 2UVR. If not, I have an old one that I would sell you.
As far as I know all 2UVRs are Z collets (the double angle collet that you are talking about). I have been using my 2UVR for 5 years and I like the collets. They are easier to change than a R8 collet and they hold long, double end mills because they don't have a drawbar like an R8. The only problem is that the collets are hard to find. Mine are pretty worn out and are starting to get stuck in the spindle. I'm considering having my spindle machined to accept ER collets, which are similar but easy to buy new out of any machine tool catalog and also hold a wider range of sizes.