Go with Option B for your CPU & MOBO! Your RAM will need to be DDR3 for this option
Can you change your HDD to either a Western Digital Black or Samsung Spinpoint F3 for your Master Drive? These are faster drives and will provide better performance to your system?
I would go with the 5770 over the 4890, if equally priced or less to give you DX11 support for down the road. If the 4890 is cheaper, I would get it since it will provide a little better gaming performance.
As for a CPU cooler, I recommend the Cooler Master Hyper 212 Plus. It is a great cooler for the price!