Check these threads out;
http://www.perth-wrx.com/vb/general-...et-driven.html
http://www.perth-wrx.com/vb/mechanic...coilovers.html
Personally, I would go something Australian, ie DMS or MCA. At least support is local if you need it or break something.
I have DMS40s on my GC - they are pretty good. With some adjustable tops they have helped the car handle the track very well. I have been told by someone with STD coilovers that my DMS were more comfortable on the street also.