Either go with the BAT kit or the Koni kit.
Koni kit: http://www.ajusa.com/cgi-bin/koni/products?ajr_skey=e1f5e75d20e6edc403033febdf92d11d
Bat kit: http://64.202.180.37/files/contour.PDF

From my reasearch the Koni kit is worth the extra 120 bucks but that's your call. Do some searching on this, there is a ton of information. If you go with the Koni kit there is a promo code that you put in on ajusa's web site that will save you $30 bucks, I think it's gift4u but searching will find it.

1998 SVT. Silver Frost. #4076 of 6535. SOLD! http://www.cardomain.com/ride/2143175