You have been told right - that PC should be able run WoW nicely at max settings.
Expect 60fps minimum in most areas, but also expect to fall to 30-40 fps in crowded areas such as the Trade District in Stormwind. A tip would be to reduce Shadow quality to 'High' and Particle Density to 'Good' - this can give you a really nice FPS boost in crowded areas and it some GPU intensive zones (e.g. flying above Elwynn forest) whilst hardly reducing graphical quality at all. I play on a overclocked 670, and I use these settings.
As for recording, it depends. If your recording just questing then you shouldnt see too much of a hit, but if your recording 25man raiding then you'll want to consider dropping your graphics settings down to keep it playable.