Just because I know you guys will be amused by it,
here are the chainsaw-based options I have found, in rising order of expensiveness:
- http://www.amazon.com/Beam-Machine-Chainsaw-Attachment-13in-L/dp/B000HD4LUK
- Amazon.com
- Lignatool Timber Cutting Guide for Chainsaws - TimberTools.com
my instinct, since I have very little money for this, is to go with the first option, and attach it to an electirc chainsaw in a 16" range. Will give me controlled cuts, should be enough DOC if I set it up right, and will let me see if the need for something more sophisticated is there.
As always, comments and advice welcomed.