Bad_Dude, to get a higher rating in the same quality you're looking for a ~$200+ server power supply, and many of those are larger form-factors. Next best might be PCPower&Cooling's largest "PC" models, but realistically you should be fine with most better name-brands in the higher W models.
You'll need to do like Codeloss, add up the power requirements of the system. I seriously doubt that your Radeon uses more than 4-6A on the 12V rail, probably significantly less. Is it even using 12V for core, memory, or just the fan?
Out of curiosity, do you know of data detailing that card's power requirements? I was going to look into that but 'so much to do, so little time'.
If I were a gambling person I'd bet this PSU will work fine, providing your system meets the other criteria throughout this thread, like using 5V for CPU instead of 12V.