Lowering GTP with 20s?

I just put some 20'' rims on my GTP and the tires are really low profiled...so iw as wondering if it was possible to lower it w/o causing it any problems...if so what brands good thanks...

Heres a pic of them..... thanks

http://www.cardomain.com/ride/477210

does anyone know???

Your already cuttin it close puttin 20's on there, if you lowered it you would probably end up rubbing somewhere, Not to mention the pogo effect you get when you hit a bump with those springs.