The 12" length would more or less duplicate the functionality of the mini-bowie, if you can even get an Ang Khola in that length. Mostly they run larger. As others have said, 15" might be a good weight for you and wouldn't sacrifice too much chopping ability.
If you can say more about the intended use, you'll probably get better advice. Otherwise, people will just tell you what they personally prefer, and their uses (not to mention physical size and fitness level) might not be anything like yours.
Basically, HI models run a spectrum from mostly fighters to mostly choppers, though any blade can serve either purpose in a pinch. The Ang Kholas are pretty much at the heavy chopping end of the spectrum along with a few other models like the Ganga Ram and Bonecutter. There are some very strong models such as the M43, ASTK and WWII that can also be considered heavy choppers but are a little more multi-purpose. Then there are models like the Gelbu Special, Sirupati and Chitlangi that are lighter weight, still good for most camping and hiking purposes, but more toward the combat end of the spectrum, and easier to carry.
These are some of the reasons that many people end up with more than one HI blade, and that's even for those who don't accumulate blades for a collection.
