Headlight Bulbs Help

i want to upgrade my headlight bulbs to xenons or sumtin brighter than stock, i tried looking online for which bulbs i can use but i cant find it any where i have a 97 XJ country I6. im thinkin i can use H4 bulbs but im not completely sure. If n e 1 can please help me and tell me which bulbs i can use 2 upgrade id appreciate it. Thanks

try these

http://cgi.ebay.com/ebaymotors/79-01-JEEP-CHEROKEE-99-00-97-EURO-PROJECTOR-HEADLIGHTS_W0QQitemZ250010878694QQihZ015QQcategory Z33710QQrdZ1QQcmdZViewItem

thanks really appreciate the help