Dampener is attached to the subframe via an E12 torx bolt. Torque spec is 21 ft lbs.
You can avoid removing that damper if you use a low profile allen key on the differential fill plug.
If you take this route you'll have to figure out how to torque that plug to spec.
Continental just updated their ECS with the ECS 02. Pricing is similar if not outright identical to the original.
https://www.tirerack.com/tires/continental-extremecontact-sport-02
HKS lists both bars individually with price but as custom make to order parts.
Personally I have yet to see a retailer list them individually instead of a set.
https://www.hks-power.co.jp/pickup-car/gr_supra/index.html