I think I'd consider installing a turbo or supercharger. You could run your stock compression ratio and allow the boost to make up the difference. It is a little easier on the starter spinning over 8:1 rather than 13:1. I think the bearings would last longer as you would only be exerting a high load only at high boost pressures.
A turbo on LP would be sweet because the fuel is already a gas and you wouldn't have to worry about the fuel 'condensing' out through the turbo like you do with a gasoline unit. Just make sure you get a big enough convertor to vaporize all the fuel.
You might also be able to figure out a way to get compressed natural gas--or
HYDROGEN
