Hi Pete,
What you have there sounds about right. I run a B4 with an 8.5 brushless, and reasonable lipo. This is still competative enough at pretty much any club meeting anywhere. Most of the other guys run maybe between 6.5 and 8.5 in 2wd, depending how power mad they are
I believe from memory the next meeting is in 2 weeks, but I received a full calender yesterday which I will post ASAP.