I put 5Zigen springs and RS struts on mine. Got the struts for free, springs for 75, and installation was 170. Lowered about 1.5 inches and rides pretty stiff but not unbearable. I like it, even though its not the highest quality setup, and for the money, and my tight budget, it was worth it. Here's a pic.
I have some RS struts that I am getting from a friend for like $10, and then I am not sure what I wanna put on spring wise. Eventually I will have a more expensive setup but I just want something cheaper for now. I will look into the 5zigen springs and a few others. Thanks for the info.
In my experience and others you will experience premature wear if you go below 1" drop on the stock RS struts.
So if your getting RS struts look at the Eibach, SPT, or Whiteline.
I found stock RS suspension with just an 18mm bar and MRT control arms to do the trick.. I haven't put on my STB's yet.
It's all a matter of matching springs and struts together properlly (a kit?) or waiting until you can do it right. Just my opinion, but what do I know I only had one of the best handling RS's around on just a good strut spring combo version 5/6 struts and STi Type RA springs.