I was able to do a balance mock up and the 5.5 oz a123 battery seems to balance the plane when placed just behind the cockpit.
So far I'm at 5lbs less wheels, pants, prop and spinner and muffler. The muffler that seems to work will be the jtec up/down square...one is on the way...nothing else barring a custom made slim Pitts seems to fit. This was going to be what made or broke this so I'm glad I've found a solution.

I think I can come in under 6 lbs and that's the goal...more as I have more news followed with pix.
Cheers,
Carl