At least get the A6, but there both dual cores, since ur getting a gpu, u could go with an athlon X4 fm2 cpu or a fx4300 as the quad core will help, and i think GW2 can use more than two cores.
the setup is good apart from that cpu but if u want a budget dual core cpu i would suggest going for a pentium g3220 or a g2030 as these offer a far better performance but u would need a diff mobo