it is prebuilt wise, but you leave out so many questions. one, you didnt even say if you do or do not have a monitor. and if you did, we dont know what resolution it is at. for instance, no point in buying a 1000$ computer with a low resolution monitor
cyberpower and ibuypower are good and are better than avadirect pricewise. I've never even heard of PCUSA. I wouldn't do that. Go to Cyberpowerpc.com and start there. Some people will tell you to build your own. I think if you have no technical experience you should stick to Cyberpower. If you do want to save a little money (probably no more than $100) build your own. I configured a Cyberpower build for 850. I searched up the parts and it was the same amount.
You can configure a pc at www.ironsidecomputers.com, pretty sure they are equal to cyber and ibuypower price wise, plus they have free shipping, wire management, h60 liquid cooling, and some other stuff. I always recommend this company cause I feel they are not as talked about as they should be.