if you are reffering to sleeved coilovers though i htink everyone will agree on Ground Controls
I have my car lowred about 3.5 inches with them for around 4-5 months and camber wasnt to bad. just be sure to get an alignment once u make a change in height
hehe i have the least popular AROSPEED coilovers and i'm not complaining.....ruffly 2.5" drop with 18" rims just needed an alignment as you will with anything else.... and as you should with any set of coilovers is get new shocks (kyb gr-2) is fine.......i just changed the rear shocks and left the front stock my ride is pretty good a bit bouncy but you can complain when you get coilovers for 80$
not the quality, but some coil-overs can allow you to change camber easily, and others you have to go to a shop (at least i was under the impression so)
The bolts made by Toyota are called crash bolts. I'm not sure, but pretty sure that they are not adjustable, so they may not give you enough positive camber, or maybe too much. If you're looking for handling, you want to have some negative camber. Just find a good balance between handling and tire life.
I have just recently lowerd my Celica with Dropzone Ajustable Coilovers. I love the way it looks, but I'm getting some nosie from the front struts. Is this a barring problem, or possibly something else? I need some advice.