The VIA stuff is pretty good these days. I do like the nForce better though. It's hard to get a more stable and simple to setup board. You can get nForce 415D boards without the integrated GeForce 2 MX, but I haven't seen one without the sound built on. Regardless, the sound built on is excellent IMO. It's easily the best integrated sound you can get. The only thing I don't like about it is a current lack of a good mixer application in it's drivers. (This may be added soon from what I've heard.)
The Asus A7N266-C is a great board IMO. The '-C' A7N266 boards do not have the onboard video. You can get this board for around $125 at most computer stores, and probably cheaper online. Another thing I like about this board is that it has hardware CPU overheat protection for Athlon XP CPUs. Up until now, only Intel supporting boards had that. If you get this board, use two identical sticks of DDR SDRAM in slots 1 and 2 for dual channel memory operation and top performance. It comes with a card giving you front stereo speaker, rear speaker, center channel, microphone, line in, and SPDIF connectors. The nForce MCP has a built on Dolby Digital 5.1 hardware encoder, so if you play a DVD movie using a program like PowerDVD it will decode all 6 audio channels without any CPU hit. Unlike VIA, the nForce chipsets use a single driver for everything. The newest version 1.05 driver is around 9 Megs and you can get it right from nVidia's site. VIA KT333 based boards are a little cheaper than nForce boards, and aren't quite as tweakable and probably just a touch slower as a result, but I still prefer them for the reasons I mentioned above.
More semi-good news is that AMD will drop Athlon XP prices by 5 - 20% depending on the speed within the next few weeks, but they are already pretty inexpensive. If you plan on waiting for the Radeon 9700 then these cuts should have already happened when you go to build the system.
Intel should release a 2.8 GHz P4 by the end of the summer, so depending on when you do this the Intel P4s may have dropped in price as well, changing the whole situation again if AMD haven't released a 2400+ or 2600+ by then.