Coilovers are the obvious best choice for adjustability, but are also the most expensive route. It sounds to me like you really don't "need" coilovers, since you're not doing any serious track racing. And if you were I wouldn't suggest the coilovers, anyways to avoid being bumped up in class. But that's a different topic all together.
I have owned and raced on a few different setups, ranging from stiffer struts on stock springs, to full coilovers. In my opinion, the best bang for the buck is.......
Srtuts: Koni yellows
Springs: H&R or Eibach
then add a stiffer front sway bar.
Your 2 will handle like a dream on the track and be more than comfortable enough for bumpy downtown streets.
"It's hard to drive at your limit, but it's harder to know where it is." -Sterling Moss