I need help making computer?

need a motherboard that can support and use these devices. memory corsair xms2 2gb, hard drive wester digital scorpion wd1200beve 120gb,intel pentium 4 3.0, xion onyx xon 303,lite on black dvd player with light scribe. i was searching on newegg.com. iam trying to play the sims 2 on a computer that iam building right now for school. i need two know a good video card to use to play the sims 2 and later other games and i like rts (real time strategy game) and i play them on my computer like command and conquer and starcraft.