I prefer the long action and use the Hawkins Hunter detachable box. Be sure to get the box with the factory rear box filler. They center feed just great.
A long will work. Get your gunsmith to throat it so most of the bullets you want to use have their base just at or barely below the neck shoulder junction when they are at the lands. This will maximize your case capacity and on these small fat cases that translates to more performance. If you want absolute max performance some people are running +P chambers and they seem to like them.I was looking into building my own rifle in a 6.5 PRC, but wanted to know if the cartridge works in a long action? Also, I had thought of going 6.5-284Norma, my understanding is they are pretty close in ballistics, I figured the PRC will have more options as times goes on. If you had to start new, any preference in one over the other?