Ambitious project
I tend to approach most projects from a practical angle first and work my way to doing the impossible for the heck of it. What you are wanting to do is a very big project that will require a skilled fabricator and a sharp boat wright to pull it off. If the only problem you have is leaning over the transom to operate your outboard, let me make this suggestion. Set you boat up with forward outboard controls, like a power boat. Then tie the outboard to your rudder to control direction, this may or may not require a different outboard. Granted the tiller will feel a little heavy but not too bad and you will have the same contol under power you have now. If you must reconstruct, buy all means do so. Just remember that any changes will change the strength of the hull. You will need to reinforce any changes you make and keep a watchfull eye until she has proven herself seaworthy. There again, unless you have considerable experience with fiberglass fabrication, find professional assistance.Good Luck and please post your solution, I am curious how it works out.