Good psu ,that suports high end gpu, under 100$

Since SLI or CrossFire isn't supported with your motherboard you won't need a power supply that handles any more than one high end discrete graphics card.

Choose a name brand such as Antec, Corsair, Enermax, PC Power & Cooling Silencer Series, Seasonic, XFX.

A name brand 600 Watt power supply unit should be able to handle any of the single highest end discrete graphics card on the market today.
 
Your mobo may not support a SLI or Crossfire but it's always good to think ahead and get the power that will require it than not.

Antec 750watt $100 + Free Shipping.

http://www.newegg.com/Product/Product.aspx?Item=N82E16817371025

That's a really good quality PSU and will run a Crossfire or SLI setup if you ever decide to_Only negitive is that it isn't modular.But that doesn't have anything to do with it's performance.