922r is a must from what I've looked into. What I'm wrestling with right now is the price. It's looking like it would be in the $3-4K range. That kind of money would buy a MAC. I know the quality is much better on the UMP conversion, but it will be a "neutered" PDW. I'm still trying to get as much user experience info as possible, but not many people seem to know a whole lot about this conversion.