There is nothing wrong with the Asus A7V except that it is old technology. It has the Via KT133 chipset which is class of 1999-2000. Certainly you can do better with something newer if you want to go with a Via based motherboard. The current chipsets are the KT600, KT800, or KT880 and will take the new OS's drivers(i.e. Windows XP, 2K) much better than an antique going in.
Also, if you go with integrated graphics you can get a fine system for far less the the $1,100 you budget. For up to date technology try:
http://www.boldata.com/
or better known:
http://www.velocitymicro.com/?source=webaward
Either will build a great machine for you well within you budget.
Jim