Yeah that is a good upgrade, but as worship said the x3 720 is a better choice IMO. If you can unlock the 4th core which many people have had luck with you will be getting a far better chip at a better price. It also has a faster clock speed and is going to be better for overclocking. Even if you aren't able to unlock the 4th core if you Overclock it you will still get better performance out of it. There isn't much of a real life difference between the x3 and the x4 processors since there isn't really many programs that fully utilize the quads.
And BTW I have that board as well and I am pleased with its performance. The bios is pretty good and very easy to navigate and find things.
DDR3 RAM is necessary for the AM3 boards so @ holysky it is a good choice. Also the prices of DDR3 have dropped so much that it is good to have all that extra bandwidth especially for a Black Edition processor if you choose to go with the 720. But either way it is going to be a huge increase in performance from your current CPU, Mobo, and RAM now.