http://www.mx5mania.com/suspension.htmTEIN Super Street Suspension - $1850.00 TEIN offers ideal suspension systems for drivers who want quicker and better response to drive freely through turns and who are in pursuit of ultimate driving experience
Koni & King Package Installed $1395.00 Koni Adjustable Shock AbsorbersDelivers exceptional road holding, responsive steering and reduced body-roll without compromising comfort. Externally adjustable for damping to ensure ideal settings for your MX-5.
King SpringsProgressive rate performance springs, recommended and used by MX-5 enthusiasts. Lower and firmer than standard springs, yet provides a smoother, more compliant ride.
I have the Koni's in my car and swear by them, admittedly, you could buy better, but cost vs benefit they do an excellent job for me.