GAZ has shocks for Esptit (frt and rr), check the catalog
Gaz Shocks | Performance shock absorbers | Suspension Kits | Adjustable suspension kits | Camber adjusters | Top Mounts | Premium height adjustable suspension kits
Also, they can fit the spherical bearing to yours, picture-number 1.
(Tim Engle wrote

The Esprit trailing arm rear suspension has a requirement for compliance. The hub carrier doesn't just go straight up and down. It's hard-bolted to the end of the trailing arm, which swings in an arc in side view. If the trailing arm swings down 10 degrees, then the hub carrier rotates 10 degrees as it goes down. As a result, the studs for the shock and lateral link also rotate 10 degrees, while the bushing eyes in the shock and lateral links do not. That creates a bind. Both the Lotus OEM rubber bushing and Lotus' own polybush kit use a softer durometer that provides sufficient compliance to absorb the hub's rotation from full droop to full bounce. It's a requirement, not an option.
If you put hard polybushings in the rear suspension, you'll create a similar bind between steel and urethane. A hard urethane will lose, while a softer, more compliant urethane will survive. Rubber is particularly good at compliance.
Have you ever replaced the Esprit's rear shocks? With the suspension at full droop, there's a significant miss-alignment between the stud in the hub carrier and the bottom eye of the shock. To ease assembly, use a floor jack to raise the hub carrier to normal ride height position with the stud horizontal. Then it's necessary to compress the spring in order to shorten the shock to meet the stud. Then they align and slide together easily. It's variation on the same issue... at full droop the stud is no longer horizontal.
That is why a spherical bushing would be prescribed.
http://gazshocks.com/