Suspension mods for the 2000 MX5

In 2001 Mazda beefed up the Miata suspension and made the frame much stiffer than the 1999 and 2000 models. My question is; are there mods for the 99 and 00 Miatas that will make them as stable and stiff as the 2001 and newer Miata's. Are the they spendy and what is a good source for them. Thanks for your help.