I have Maximum motorsports solid drag race lower control arms and UPR double adjustable uppers. They are both of fine quality and they've really helped to anchor the rear of my car. I've heard both good and bad things about Steeda, but no personal experience with their suspension products. Another good company I hear positive feed-back on is Metco. Rather expensive, but definately high quality parts. If you haven't invested in a set of sub-frame connectors(and I'm going to guess you haven't, judging from whats listed in your signature), then now is the time to invest in some. They will help to stiffen the chasis and keep it from bending and twisting in turns and in hard launches. Also, as mentioned above some sticky tires would be a good investment.