Here's mine!
I used AVOs which are 10" compressed, 15" extended length, from memory. Springs are 300lb, mainly due to the extra weight and power of the Impreza turbo engine. With softer springs the rear squatted way too much!
There is a site somewhere on the web which has a table with a direct corrolation between torsion bar diameter and spring rate at the coil-over...
Hope this helps!
Rich