If you're getting coilovers and plan to change the height often, then a non-fixed bushing might be a good idea. I have PCI sphericals in the trailing arms of my teg and they perform great.

Clocking the bushing only requires a bit of thought before you start taking everything apart, and you have to have the car at the height you want before you get going (i.e. you can't install a new RTA bushing and lowering springs at the same time). Just get a ruler and line it up parallel with the metal centre part of the bushing and mark that line on the trailing arm. Now you know exactly what angle to bash the bushing in. Just don't rotate it the wrong way :/