If you are ready to use money on a AMD 760 chip you shure should buy it, but VIA will suddently launch a new chip witch supports the same things as the AMD-760. As an example: Dual TBird, DDR and alot of other things. The KT113/KT113A is far more used, and therefore more stable, but the AMD sure supports new fancy features!
But the idea of AMD making chipsets is just because VIA can get some inspiration from AMD and make another - faster - similar chip.
The KT113A would be my choise but it's individual, anyway.
🙂