Hey Frank,
I was curious to see if you have made a decision on your engine, I considered going electric a few years ago when I was faced with an unexpected engine replacement (P31-2 Yanmar 2GM20). For me, the biggest factor was how the boat is used. Most of the time I use the boat for day sails or a couple of nights out on the hook so in that case, going electric would be a good option as the batteries can be charged back at the dock. I also go on longer cruises (Bahamas) which presents charging challenges, I didn't want to go a marina every night for shore power or cover the boat with solar panels and wind generators. Having said that, Sailing Uma on You Tube has been cruising electric for years. In the end I went with a new Yanmar based on my longer range cruising plans. A buddy in my sailing club converted his P30 over to electric about 10 years ago and is very happy with it for local day sailing and racing. Going to electric will probably narrow down your buyer market if you sell the boat, I'm not sure how it will affect the selling price as unlike electric cars, electric boats are still something of an oddity. You might ask a broker what they think on resale value. You'll have to do a trade study between electric vs diesel but I'm thinking electric will have a higher initial cost. A boat with a fresh diesel is going to command a much higher price than one that needs a new motor and will be much easier to sell.
Let us know what you decide!
Joe