One good thing came out of those early tinkerers. Their proof of Concepts contradicted Toyota's notion that no one wants to drive electric.
Anything that is not designed as an ev would be a nightmare to try and modify to make it into something you could just buy, the chances of you frankensteining batteries into a regular prius and then modifying the factory toyota programming to get it to work decently well are close to 0% and definitely not worth the time and cost involved unless you already know what you are doing. It would be much cheaper and efficient to just buy a prius prime or any other plug in hybrid or full ev than to try what you are asking.
