http://leginfo.legislature.ca.gov/faces/codes_displayText.xhtml?lawCode=VEH&division=16.7.&title=&part=&chapter=&article=
you will have to contact your local county and city to see if registration is needed
they are currently off on a tangent discussion over there about kits. the first couple of pages are relevant and easy to follow ,but,,, close to two years old.
technology has changed a bit, might be time to start a new thread?
local bike shop is the way to go, they should service and warranty it should you need it. all are name brands and the warranty should ease your mind.
good luck!
the only advice I can give, and that I haven't read or viewed is, the mid mount motor e bike I got feels much more "connected" than the hub motors I rode.
just felt more natural . it's an I-zip edge. fairly new model. good luck!
old fart here as well. just pulled the trigger on my first e bike and warranty and store where I got it were the deciding factor.
just look on this forum to see the number of makes out there. could drive you crazy.