Those are solid specs, and I have to agree on the Asus A7N8X-E Deluxe, which is what I run in my main box. If you want something cheaper than that and don't need all the bells and whistles, the ECS N2U400-A would be another good board unless you really want to OC the hell out of your system. The N2U400-A does not have SATA like the A7N8X-E Dlx does, but if you want a cheap, solid motherboard, that's an excellent choice.
Besides Antec, you might look at some Sparkle/Fortron (same company, just different brands) or some of Thermaltake's power supplies, as these seem to be quite good.
As for RAM, get PC3200 from something like Corsair, Crucial, Kingston, Samsung, GeiL or Mushkin. I wouldn't get any less than 512MB, and at the prices these days, you really should at least consider going to 1GB.