Actually, the PSU will be the least of your problems. They'll have enough power supplied to run all your parts, but you won't be able to upgrade it very well. The Graphics card is what your problem will most likely be if you're looking to spend around 800. The Mobo is always going to be simply decent, the RAM is going to be as well. Best option would be to build your own, and you wouldn't even have to put it together yourself. Certain places will collect the parts for you and build it for you, and all you have to do is tell them what you want to put in it. Fry's is great for this if you have one near you. Not sure of any other places off the top of my head, but I'm sure any place that specializes in computers will help you out with this.