General suspension question. help.
 

I am not good with all that shock & spring theory.

As I understand: for sport suspention there are two parts: shock itself and coilover spring (with nut and thread for lowering your car).
http://www.mx5mazda.co.uk/commerce/p...koni_shock.jpg
http://www.speedstash.com/dropzone/coilovers_red.jpg

What I don't understand:
1)How do you know that Eibach shocks willbe compatable with Bilstein coilovers(example)?
2) Seems that some shocks comes with threads already, are those already full assembled kits? http://www.forwardmotioninc.com/html.../coilovers.jpg
3) some shocks come with varible dampening, which you can adjust by the knob on top or electronically the shaft.is it correct?
4) There are some varible stiffness springs springs, so what set up is best for racing: shocks+springs (both not adj.) , varible springs+shocks, electronically variable shocks and variable springs?

And can you recomend some shops or dealers who can get some of that stuff (^^^) for a good price and it won't takes us 3 weeks to wait. We need full kit springs and shocks for Corolla 2001. Thanks you very much.

bump
looking for the same answers for a 92teg