Asus motherboards are in my opinion the best motherboards on the market. And this one is designed for the latest AMD CPU's, so yes, that CPU will fit, and all video cards made today by either AMD or Nvidia will work with any modern motherboard.
And yes, that should make a good gaming system.
As for memory, just to be certain that you get compatible memory for this motherboard, download the "QVL" which is the Memory Compatibility list. Anything on this list has been tested and approved by Asus. Download the latest version of the QVL at:
http://www.asus.com/us/Motherboards/M5A99FX_PRO_R20/HelpDesk_QVL/
If you can afford it, I would buy either a 128GB or 256GB SSD. Samsung is my prefered SSD brand. This will dramatically speed up your boot times, and if you install your games on the SSD, but have the game save its data to a hard drive, your system should be very quick. If you cannot afford an SSD and a hard drive, then at least get yourself a 1TB hard drive for now. Try to save up for the SSD later on though.
Hope this helps you...