Installing Vista takes too much time in lots of systems, not just Asus. Just be patient as once installed it runs fine.
I don't understand why you're buying a motherboard with on-board video for gaming, but I presume that you are interested in other features. That wouldn't be my choice because a Gigabyte GA-EP45-UD3P or GA-EP45-UD3R if you don't need Crossfire is better. Asus also have better motherboards like the P5Q Deluxe.