You might try then a custom built from Monarch Computer. You will have to cut it tight to get a "high powered gamer" for under a grand. The monitor will cost you $200 or $300 for a 17" flat panel, leaving you only $700 or $800 for the box, which gets you a decent minimal gamer, not a high powered one.
If you want them to build and test it for you, I suspect (not sure) this means you will have to buy at least one small disk from them, for perhaps $50 to $100, which will be a bit of a waste. But unless you build yourself from the parts, you kind of have to put up with that.
I'd suggest giving Monarch a call. One of the reasons they get high ratings is because they have capable people on the phone who can match up your needs with what's available.
The closest that I see, offhand, that matches what I'd recommend and what I understand of your needs is the Monarch Adversary Value Gaming Desktop Special (PCI-E) , for $845.00. It has a case, power, motherboard and memory that I'd recommend. Unless you are good at this, you may be hard pressed to get as good a system for less money by buying parts and reusing the disks and dvd you have.
Thank you, I will try it.