awl3662 wrote:So far mine is working great. Really fast and really quiet. I really need a new graphics card and a PSU. Any suggestions would be greatly appreciated 
As a comment, mine has been working great also. Got my replacement drive from Newegg(an add on, original from them was DOA) and it is working fine also.
To answer your question, I have no idea. Its like asking me "what car should you buy". Each of us uses a computer(or car) differently. Some for games, others for CAD/CAM, others for business, still others for audio/visual, and the list goes on. Plus most of us don't just do one thing on a computer. Once you know what you are going to do, then some Googleing, research, reading reviews, and finding one in your price range is in order. There is always the, check what is on sale and research that card to see if it will do the job. There is no one or easy answer here.
Once you choose your graphics card, check to see if the specs tell you how much power it requires. This will give you an idea of how much additional power is required. Hopefully it will give you an exact number and not say something Jatravartid like "you need a 450 Watt supply". How do they know what else you have in your system(motherboard, CPU, memory, drives ...). Although in the case of this computer, 450 Watts will most likely do everything you want with power to spare even with a new graphics card. You don't need a 600-850 Watt supply, that's overkill.
If the computer is doing the job for now, I suggest you take your time. Spend some time doing the research. Find the card(s) and power supply/supplies that will do the job, then check around for the best buy or sales(they are going on all the time) on them and save yourself some money in doing so.
As and example I spent close to 6 weeks looking for a computer to buy. I had already figured out what would do the job for me and had several choices in mind. When this Woot deal can along it actually had everything I wanted plus more and at the same price or less then the ones I was looking at. I knew it was what I wanted. Then it took me 2 hours to talk myself into actually parting with my money. Strange how that works.
I'm guessing this is not the answer you were looking for, but I hope it helps.
OK, I've tried twice to fix the line in the 3rd paragraph, but it keeps coming out wrong when it displays. Instead of "something 's t u p i d' like" it keeps coming out "something Jatravartid like". Really, a species in The Hitchhiker's Guide to the Galaxy! What gives?
tolerance: a fair, objective, and permissive attitude toward opinions and practices that differ from one's own.
BOC: 4 Including the very last Woot!-off B)C. One of the lucky few.