The A10 is an APU, which means the chip is divided into two, one section being the CPU and the other the integrated GPU. Hence the processing power of an APU is very less compared to a CPU.
As you are using a discrete GPU, the GTX 660, which is a great performing card, you only need a CPU, i.e in this case the FX 8350. The 8350 will be far far ahead of the A10 in terms of performance. So yeah, get the FX 8350