Hey sounds like a great project , I am coming into the discussion alittle late but what the hay . I to am interested in performing a similar mod to classic cars , I have a couple that would be more fun if they were "economical" . If you do a little research and have decent mechanical skills , it is not rocket science , but for pure simplicity the right diesel would be fairly easy , or pure E.V. but range becomes an issue ..... so hybrid it is . the V.W. 1.9l diesel is a great option , or a diesel out of a Jeep Liberty...... I may stay just Diesel or maybe propane . good luck , to you , go search some of the homebuilt E.V. sites and pages
I will check back in a few days cheers