Lexus IS300

On ebay this one guy said that the Lexus IS300 and the GS300 both have the supra engine. is this true? here is the link... http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=1829912774

i'm gonna take a stab into space and say the supra and the is300 have diff engines.. although i like the is300 a lot more now.. more and more anyway even though everyone has one i might just look into getting one.. i hate to admit it... but i just might...