Love the bike and am very much enjoying the progress you are making.
I would echo what supershaft said earlier... start with getting the bike running to assess the condition of the top end and transmission.
If the cylinders need boring, heads worked on and transmission rebuilt ( which would not be much of a surprise given the long storage in the conditions you list) you are talking about spending a few $k's...
The bike will be worth the investment, but you may find you are not an "airhead" guy after some miles.
Assess the mechanical health first, and do everything else second