AMD 3200 ?? -> If you want to go lower than a 3500 (which for cIV is doable, just not bejeesus) better get a 3000. The 3200 is quality-price ratio not good. The 3500 really has an excellent prive-quality ratio. The 3000 has an ok price-quality ratio, but the 3200 is too expensive for what it gives you.
The Mobo I recommended, Asus A8N-E is a very limited motherboard, but strong on exactly the elements that cIV uses and rather cheap. And being an Asus, it is good quality, not crap.
The Nvidia is the manufacturer of the Geforce card, so the "Nvidia 128 MB 6600" = "Geforce 128 MB 6600".
Grah: does cIV support dualcore? I don't know if it does.