I did the energy suspension trailing arm bushing when I did my brake swap. It was a pain in the ass to DIY, but the stock bushings were shot, so I kinda had too. I would reccomend getting the Prothane trailing arm bushing over the ES. It comes with the crossmember already installed, which makes the whole process a little easier. I think its worth it though, that bushing is one of the crappiest OEM bushings on a civic, IMO. For more information on replacing the bushing, do a search in my name, or bumnah's name... we've gone over it many times.

Theres a good DIY for the brake swap on hybrid garage

:EDIT: Which differential did you end up getting? Enjoy the new motor!