Good choice on the tekin rs. I recently upgraded to one from my havoc. Might want to see if someone can hotwire it for you, it really opens the thing up.
So far I've run it with a 17.5 ballistic with good results. I have a Team Epic D3 I want to plug up but I got one with a bum sensor board... (should be here today, I'll post what I think as soon as I can put my hands on it)