You should get an axp 1600 and an nforce motherboard, since you arent a gamer an nforce comes with great sound, good video and a network card, it saves considerable money over buying a seperate sound and video and nic card in addition to a motherboard.
The video dosent suck, but it wont be playing games at 1600x1200, but I dont think you are looking for a gaming rig.
"The Cash Left In My Pocket,The BEST Benchmark"
No Overclock+stock hsf=GOOD!
A P3 would likely not go half the speed the AXP 1800 would give you, and forget any P4s for such rendering, the Athlons are known for these. So yes an XP 1800 would be perfect and like Mat said, the Nforce is not bad for people who won't go playing too much games, and it has a very stable chipset curtesy of Nvidia!
Get Windows XP with it for optimal use of your multimedia rendering and full stability.
The other day I heard an explosion from the other side of town.... It was a 486 booting up...