Dave,

I can't say that I'm familiar with the Himax outrunners but a 3-cell Kokam 3.2AH pack is lighter and provides plenty of power with the correct motor for the Magister.

You may be interested in my latest upgrade project. I will be testing the new [link=http://www.hobby-lobby.com/magister.htm]Hobby Lobby Magister Upgrade[/link] as a "Part 2" article except using a 3-cell Cellpro Kokam [link=http://www.fmadirect.com/Detail.htm?item=2077&section=45]3200mAh pack[/link] which is the same as your Kokam pack except with a node connector for balanced charging.