As a beginner, I'd recommend the Asus primarily because if and when you want to overclock, they are about the closest to a one click solution you will find. Another reason I like Asus is that they always have a top notch product in both the MoBo and vid card arenas. Having the same vendor when troubleshooting makes life a lot easier as TS can't give you the "it must be the other guy's hardware" line.
A big factor in your selection will be whether you will, now or in the future, use two (or more) vid cards. That puts you in the position of having to decide between nVidia's SLI or ATI's Crossfire.
If money is truly no object, it's hard to find something hotter than the Striker.