I just bought a 1963 +4 that used to live in Hawaii and doesn't have a heater. I live in Massachusetts and would like to be able to drive during the Autumn and Spring without the risk of frostbite. Can anyone recommend a heater to help keep my toes where they belong?

Thanks

1963 Plus 4
1990 XJS convertible
1979 Triumph Bonneville
1988 Harley Sportster 1200