Threw this out there under green building, but maybe better under this catagory.  We want to drywall/texture the wall of our log home to improve r-value, reduce dust, and make the interior tighter.  We do not want to mar the logs for any future sale etc., so we do not want to use spray foam insulation.  The walls will be furred out with 2x lumber away from the logs, plumb.  Do i need to worry about a vapor barrier.?  Any other things to consider?