Exactly. I have a koni yellow/ground control setup, and I have had it at a functional height and slammed. When it was slammed it handled ok, but at a functional height it handled amazing.
The koni yellows will definitely make a difference in your handling, but they will have zero effect on your ride height.
If you're looking to be slammed go with function and form type 1's, like teal said, which will run you about 550-700$ depending on where you get them. They are an excellent entry level one piece coil over with adjustable ride height, but with fixed dampening.
Another option, which is cheaper, would be to go with racelands. You have to use your stock top hats, bit you adjust the ride height down about 4 inches. They'll run you just under 400$. They're pretty popular with the budget stance crowd, especially in miatas and VW's.
Hope that helps.
