First comment is that the specification in your link is incorrect.
The Asus A8V-VM SE motherboard has a VIA chipset.
This probably doesn't make a difference to your choice.......but as a general comment,particularly since you mention Vista.It will certainly be ok with the X1600.
I personally didn't find my VIA chipsetted motherboard ran very well with Vista.The latest available VIA chipset driver package contains mainly older drivers that pre-date Vista by a number of years.They are not thetefore optimised with Viata in mind (but do work).
Other comments are that you are going to be severely restricted by the Socket 939 as to the best cpu you can use,and same goes for the DDR memory.
Vista really needs a fast dual core cpu and 2GB of RAM to work at its best.Few cpus are availablr fot Socket 939 and DDR memory is generally significantly more expensive than DDR2.
If you are wanting to go with Vista you are probably better looking at a more extensive upgrade.
However you don't say why you are upgrading the motherboard.
Can you give us a few more details of the reason for your choice.......like transferring existing components to the new mobo?
If so what components?