I would leave it at 140 or 150 from the LE, thats pretty close to where my Twister is. It will fly fine to start with that CG I am sure, then you can adjust as required. There has just been a huge discussion on the NSRCA list about trimming and it really relates to this. Its worth going to the NSRCA website and digging through the list archive for the past couple of weeks and reading all the trimming threads.

The 451 or 351 will do the job on rudder, the 351 is really powerful and quick and requires a good setup otherwise its easy to get a twitchy looking rudder input., but otherwise works perfectly.

Akiba was running a 451 on his rudder in Argentina, so don't worry if thats what you have