I'll explain the psu hatred a little. Don't worry about thinking you fucked up, you didn't. You like most PC builders got caught out. I did, and most of the people who have PSU problems also did.
PSU's ATM are in a bad position. They have a wattage system that doesn't work and is open to abuse by manufacturers.
ATM a psu only has to hit it's target wattage to be rated for that wattage. Unfortunately PC's don't spike with wattage they draw a constant wattage from the unit.
There is also another flaw in the system. A psu is rated on it's total wattage output and not the wattage per rail.
As you probably know a PC draws a few different voltages from a PSU. Those voltages have a rail of their own. So the 3.3v rail can do a set ampage, the 5v will have a set ampage, the 12v will have an ampage ect ect.
The problem is the total of all of the power drawn is the rated wattage for the unit. And in older design computers where the 3v and 5v rails were heavily drawn upon the PSU had is strength here. In a current machine the 12v rail is the important one. You don't need an expensive PSU, you just need a branded one that lets you know the PSU has it's strengths in the 12v rail.
Manufacturers continue to pump out high wattage PSU's that are strong in the 3.3 and 5 volt rails. These psu's are all dangerous in a modern machine as the 12v rails are often weak, and with the draw on the 12v rail they become a very real fire hazard.
your PSU sticker should look like this.
Notice how you can see the Power available per rail.
If you put a link up for your local hardware site i'm sure a few people will look at the range available and pick a Budget PSU that will be safe and powerful enough for a crossfire system without breaking your bank.