Well, you're on the right track if you want to lower the car and still do ok at autox. ST and HR are both good options.
Stuff I see as doing it wrong includes: cutting springs, doing springs but no damping, springs with poor damping, and springs that are not stiff enough for the suspension travel available.
Parking Lot Hero
2008 WRX daily driver
2003 ZX3 23D Autox Car 42 FSP
"Hella Functional - Raced, Not Hard Parked"