Alright, so I recently bought a new Graphics Card, and of course I didn't research enough, so yeah, it doesn't exactly fit in my case! And to top it off, I don't think my Power Supply could run it, even if it did fit! So, time to shop around some more. I'm not looking to build the next big super computer, I'd just like the bare minimum I need to run my system with what I've got, here's my specs. =)
You don't want to get "bare minimum" to run anything. A PSU is probably the most important part in your computer. If that dies, you could destroy your entire system and all the data on it too costing you more than you paid for the PSU itself. Not really worth the risk.
You want a good quality PSU that will easily run everything you got with some extra room to move. With your rig I'd suggest at least 550watts with good amperage (more than 30 amps) from a company that's known for good PSUs.
I have been around and run "BBS's" from back in the 80's from befor what is now called "the internet".
If you want the only PSU that I myself use and build for others with...get a PC Power & Cooling PSU.
If you want the next step down get a Silverstone PSU like Falcon Northwest uses for their 5-15K USD custom builds.