springs are rebadged Eibach, and I think their shocks/struts are Bilstein.
Tein is really good, so card00d85 you are just running on Tein S springs right? Perhaps look into Tein Basic Dampering kit or Tein Super Street Damper if you have some extra cash. Otherwise Hotchkis is one of the best, maybe the best suspension product for the Celica.
Sway bars will also dramatically improve your cars handling, it will make it stiff mind you but that's the idea and there are also strut tower bars which I believe go underneath the vehicle. The only "downside" to sway and strut bars is it can make the car respond so quickly that if you find yourself in a soon to be accident position that you may jerk the wheel too quickly and end up oversteering and loose control or just end up steering into something. But I am sure that wouldn't be too big of a threat once you get use to your set-up.