There have been many studies, most motherboards don't make a noticable difference in computer performance. However, ASUS is one of the best brands (if not the best) for motherboards. Just make sure you have a graphics card to put in there.
In honesty if I had the choice, I would actually go for one of the P5Q series instead. Unless you plan to use SLI the P5Q utilizes Intels P45 chipset which is better in terms of performance and stability.