GPU only. I'm looking at a total budget of around $1000 (likely more), with $390 already spent on case, PSU, HDD, and monitor (expecting $45 in rebates). Looking to spend around $350 on CPU + mobo after deciding on a GPU. I'd say that GPU is my priority over the remaining components given my typical usage.
GPU must be the last priority since you can upgrade it later, but not with CPU and Mobo.
For $200 you can get GTX460 just like matto said above...
And don't forget do not cheap out on PSU, it's the most important thing inside your PC.
1. If the ATI 6900 series is going to retail for about $300-400 upon release as I've seen suggested, is that still going to be worth my while given that I don't plan to do any intensive gaming?
2. Will the power supply that I've purchased (listed in the OP) be sufficient for the ATI 6900 or GTX460? I suppose I could ultimately return it, but I've been under the impression that it should be fine for my needs.
Also, I was advised in another section of this forum that, for my needs, I should base my CPU/mobo purchase on the GPU. Is that bogus?
That may be true, but I think the article and what everything is saying is, in future upgrading your GPU will give you the most noticeable performance increase in terms of demanding games. Having said that, if you want to upgrade your system 2 years from now you won't be able to put in a more powerful card without a more powerful PSU. Getting a rock solid PSU is of first importance in building a system. Your PC isn't going to be worth much if it won't actually boot up! Or run for longer than 5 minutes due to instability. wa1 is right, it is good to heed his words.
Your choice on PSU and Monitor are good. You can run dual cards with that PSU.
You will better if you decided CPU and Mobo first, after that choose GPU. If your mobo support dual cards then 2x GTX460 are enough to maxed out everything at 1920x1080.
If you prefer a single card then you can go with GTX470.