What agp Video card only needs 250 watts of power, and can run doom 3 on high setting?

i have an old dell dimension 4600 that has a pentium 4 2.88 ghz processor, 1gb ram, and a 250 watt power supply. what graphics card can i buy that will be able to older shooter games (like doom 3 , far cry, and half life 2) on high setting that only need a 250 watt power supply?