ATV conversion

I am looking to do an atv conversion within the next couple years. I was thinking about using this -

It will be a 48v system with 4 12v batteries, or if there’s room and I need more range, a 4s2p configuration. I want to put in another motor to act as a generator and increase range. Does anyone have any experience with this?

Last thing is a donor atv. How can I get an atv for the conversion at the cost of about 500 dollars?

Thanks for any help, Riley