So far as the PSU's concerned, you've got the right idea. 500W with a single +12V@34A is well spec'd, but unfortunately there are a few problems with it.
The unit is rated to a standard that doesn't conform to ATX specs. Specifically, it allows for a voltage tolerance of 10% on the +12V load, whereas ATX calls for 5%. This is what allows it to claim the larger total output. While it is, of course , capable of staying within specs, it is not capable of doing so with anything resembling full load. The crossloading performance is quite poor, which could be an issue depending on what you end up using with the system.
In addition, the unit is made by Youngyear, who don't exactly have a great reputation as far as PSUs go. It should work, but I wouldn't be inclined to trust an expensive system like that to it.