High Sierra
I was thinking about your CofG problem and the motor you were going to use until you got a bigger unit. Due to the size of the cowl and the spinner have you thought of putting some spacers between the engine mount and the firewall to shift the motor and mount forward. With the size of spinner the temporary mod may help reduce the amount of ballast to correct the CG problem and not look to out of place. I have done this on a CAP 232 and moved the cowl foward which gave me the correct CG and it didn't look out of place. When I got he heavier motor I removed the spacers and shifted every thing back. Just a thought.
LAinWA