Best Springs For Ride Quality and handling? And Drop of course :)

Heres the deal,

The next mod im thinking is going to be dropping the car,

Now Mustangs seem to ride really high from the factory,
And I want to get a set of lowering springs,
I have KYB Shocks (non ajustable) all round,

But my ride quality sux big time, AND one side I noticed it higher than the other by a fraction,
So It looks like my Springs I have now are toast

What better reason to replace them
I want a nice drop, Something really noticeable, but I want the best ride quality possible, I can always get stiffer shocks down the line,
Whats the best for what I want?
I dont need a hard as balls stiff suspention, Im not doing drag lanches every weekend,
I just want a really nice riding car that dosent crack my arse bone everytime I drive over a matchstick,
So whats out there?
How much, and where?

Ive heard factory "Bullitt" springs are good? True or BS?
But I want a niiiiiice drop, no 7/8 of a inch crap, and I dont want my suspention geometry to be screwed up and cause uneven wear and other problems,
So,
Nice drop, nice ride, and no problems,

Are the C/C plates REALLY needed???

Anyone know a place online that sells Bullitt Springs??

and is it only Bullitt springs that were lower than stock from the factory?

I want to make my Wheel arch tire gap dissapear, Thats the objective,

anyone?