I've got a 20+5 14k Gooseneck LoadMax trailer to haul my puller. Thats basically all I use it for. I went with the 14k trailer becuase of the lower initial cost, less tires to maintain and less trailer weight to pull around all the time. I have a RCLB puller and it fits on the trailer just fine. I pull it back some to take some of the pin weight off the tow truck ('05 CCSB). Just remember that the 14k lb rating of the axle/tires is with the tires at max psi (80psi usually). And I believe that weight rating is at 65MPH. So if you are one of the guys that has to drive 75+ MPH on a hot July/August day, the amount of weight that the tires will support is decreased as the speed goes up. Heat is what kills a tire, so if you are flexing it more (faster speed) and the ambient temp is higher, the weight rating is lower.
Good luck with your trailer search.
Oh and last year I put a MaxBrake (hydraulic over electric - ties into the hydraulic brake lines) brake controller on my truck. I will never go back to the other styles of elctric brake controllers. The MaxBrake is well worth the price. The truck/trailer combo braking action is perfect. The wife drives home from a lot of the pulls (too much celebrating
) and she loves it because the brakes act just like the trailer isn't there. No adjustments, no locking/unlocking when hitting bumps, etc...