Welcome Jon!
Electric car engine on a bike!
Sounds like a cool project but your pics are not showing up for me. Can you check the privacy or share settings on them in your google account so we all can see? I am really interested in how you mounted that all together.
In general... I would be worried about ground clearance via suspension as well. The pregen ninja's aren't really known for their spectacular springs. It sounds like you know this already but maybe you can just respring the stock tubes and totally replace the rear shock to something more suitable that would require much less customization and be a lot cheaper.