Suspension Mods Input Needed !!!!

[WILDTHANG]

I have an 02 GT convert and I want to lower the car and correct the suspension geometry. I am no going to race the car, but I want to drive it the way it is meant to be driven (with total control). It seems to me that lowering performance springs aren't the way to go. So I have been looking at new tubular K-members, coil overs, caster/camber plates, bumpsteer kit, etc. and for the rear, new lower control arms, torque arm, panhard rod, etc. Is this my only choice for suspension correction and if so, who has experience with what company's products (good & bad please)? I've heard good things about Griggs (2nd hand), 4000 bucks seems a little steep, when their are other companies out there advertising the same products for half the price (aside from struts/shocks). Which brings me to my next question, who makes good struts/shocks that perform and last? Also, How do you figure out the best spring rate for coil overs, is there some rule of thumb? Too many places pushing products, I just want it right the first time.

Thanks