There are many suppliers of parts. The easiest solution is to replace the engine with an electric motor and the weight won in gutting the motor and tank by batteries. The gearbox is often kept for simplicity. Kits are available from sites such as https://eveurope.eu/

The biggest challenge for me has been local regulations. Check those.

The CR-Z is a historic piece imo. Kudos on keeping it on the road. You'd have to replace both engines in your case but perhaps the driving dynamics can be kept.