@Filmstress
First, I do not see the specific model and year of your boat which is crucial to get a better response. What is the model and year?
To add electric engine either way will be costly. If you ever resell the boat, you will not get back what you put into your sailboat. Due to age, what is the condition of other gear and boat as that would have to be considered?
The early Hunters did not have much room which is why the specific model and year. Hunter started off with a 25 footer sold to a friend of mine delivered by Warren Luhrs himself in the 1970’s