what headunit do you have? Get the Infinity Kappa Perfects for the front, and try and get their 6x9's for the back. The 6x9s are gonna give you your bass, but don't expect as much from the 6.5"s.
you can find the Kappa Perfects for ~$220, which is pretty good since they're MSRP is ~$400. Try Ebay or www.etronics.com.
http://www.etronics.com/product.asp?...ore=&catid=362

http://cgi.ebay.com/ws/eBayISAPI.dll...sPageName=WDVW