Running 275/40-17's in front and 315/35-17's in the back, front end dropped 1.8", back end down 1.0". They (STS on Rt 18 E. Brunswick) had no problem aligning the front end to my specs. Most other shops wouldn't even touch a lowered car. I had it aligned to a set of specs a buddy of mine recommended based on road racing experience:
Caster: +4.0*
Camber: -1.0*
Toe: 0.1
Car handled well, and had no unusual tire wear.
There's also factory and "lowered" specs in the 4th Gen FAQ:
http://www.f-body.org/faq/4/4_5.htm#ch4_5c