Thanks for all your replies!
I know that trying to match a Lotus in handling with a 30 year old 911 is kind of a BHAG.
. Altough I must say that arrowSC is doing a splendid job with that Lotus in his video. I think an Elise or even an Exige would have a hard time keeping him off.
I think my questions can be brought down to:
Should I go softer or harder torsion bar wise to make my car handle better AND if I go stiffer, will I still be able to use it for a relaxing cruise?