Need help please on deciding the best option for replacement stuts/shocks on a 1986 944na. Current fit 944.343.031/11 left and 944.343.032/11 right. These look like they are rebuildable (they have a treaded collar holding the inserts in)and have springs fitted with two blue dashes of paint on each spring. Also have a spare set from a 1987 944 Turbo 951.343.031/05 and 951.343.032/05 respectively. The car is for road use only but I have upgraded many components as they needed replacement.

Questions:

Are my struts rebuildable and if so, what inserts should I use for a more responsive ride?
What rate are the springs fitted and what should I use on the rebuild for a slightly firmer ride?
Will the turbo stuts fit my car and is there any advantage in using them?
Are the turbo struts rebuildable and again what strut inserts/springs should I use?
I have seen kits for adjustable height strut conversions. Are they any good? Cannot afford fully adjustable coil-overs but these seem like a cheaper option for road use and allowing the option of slight lowering at the front. Again what springs and inserts are recommended for these kits for a slightly firmer ride and better response than stock?

Any help appreciated, thank you.