Glad you picked up the Murray cruiser. That's my
Murray in the link. Don't worry about swapping forks, they're fine if you don't mind having no suspension. Your bike is in MUCH better condition than what I started out with. I made two modifications. The coaster brake isn't enough so I added a side pull caliper to the front wheel, big improvement. I also welded on the front motor mount because clamp-on mount wasn't secure enough.
In my mind this is the type of bike these motors are made for and the finished product looks just right. I'm loving it.