Peter , with a light car and a great deal of unsprung weight in that live axle i dont expect too much in the ride comfort area , but if the springs are due for repacement then i may as well pick the best option which looks like the assimetrical springs you recommended. If i then start to experience axle tramp i can always add anti tramp bars like the ones offered by Mullberry without compromising the ride .
I shal call the factory and check if they stock a set for my car .
Dave