1gb vs 2gb is not much of an issue, I think.
Since integrated graphics uses system ram, the faster the ram the better.
You bought an apu, and that really means that there are no good upgrades available.
A discrete card throws away the value if the original graphics.
I think you could crossfire, but dual cards bring on their own set of problems such as tearing and stuttering.
Even if you installed a very strong discrete graphics card, you would be left with a cpu that does not have strong individual core processing power. You could upgrade to a cpu with more cores, but that will not help much since most games depend heavily on the strength of the master core.
What you have is what you will have forever.
If you need more cpu, look...