ATI Radeon HD7770 is the highest I'd consider going on a CPU from the November 2002 to April 14, 2003 era.
Your particular Pentium 4 3.0GHz HT may have been released on 14 April, 2003 but there was a faster processor on the market by Christmas 2002.
PS: You're probably after an AGP 2x/4x card too!