RE: Is this a Willard?
On any new engine avoid the Hurth series of trannys like the plague !!
OR get one at least 2 sizes bigger than "recommended" .
Twin Disc is my first choice , if you can fit it.
The 3 cyl is far smoother than the 4 with less effort , 3 or multiple of 3 if you like smooth.
I would also install a "lift muffler" in a large size , the only noise from the exhaust will be the trickle of cooling water splashing down from the exhaust fitting.
A Side exhaust has loads of advantages , as does the "North Sea" setup with exhaust thru either side.
IN AK it might be moot as the dry stack would be first choice to keep the maint at a minimum .