When I first drove the car post-conversion I was impressed at how heavy and over-loaded it felt- Weighing it confirmed that with no driver/passenger the weight was about 2700 Lbs (1200 Kg), which coincidently is about even with the gross vehicle weight rating of the car. I decided to install stiffer springs and more powerful shock absorbers to try to improve the ride. As well the car had seen 100K+ miles as a gas car, so the original equipment was worn out.
I decided on an adjustable coil-over kit from Ground Control with 350 lb/in springs and KYB AGX shocks. I installed them myself, then had a professional four wheel alignment done. Details from that project are in this post. It still feels heavy and is lower than stock but it’s worlds better than it was. Total cost was about $1000.