tvanbroekhoven, Tim;
Two big factors you are fighting are weight and center-of-mass; the Lotus has a 911SC on both accounts.
You can address these to a point but you lose the nice street-ability of your SC.
You are correct; the ‘harsh’ ride is most from the stiff shocks.
Keep the same (or slightly ‘softer’) shocks and enlarge the torsion bars to 22 mm front and 30 mm rear.
You may want an adjustable ‘through-the-body’ front sway bar and reinforce the rear sway bar attachments for larger sway bars.
You also may want to just waive the Lotus by and enjoy your nice (street) 911SC.
If you want to flash your light and go on past, build yourself a lightweight, low-CG ‘sleeper’ that appears the same as your SC but is all race-prepared chassis, appropriate track tires and 300+ hp underneath.
Best,
Grady