This question has been on plenty of forums and is really a difficult one to answer because there is no single "best" between the A series and FX series processors. To get started, I'll talk a bit about each.
A-Series Processors
The AMD A series processors were mainly a combatant to the lower end intel processors. They were designed to give good low to mid range proccessing power while offering great integrated graphics to come along with them. They capped out at 4 cores, but still offer stunning performance for low-end and mid-range PC users. AMD has gradually expanded them, creating higher-end ones such as the 7700k which where designed to handle mid range gaming.
FX-Series Processors
The AMD FX series was designed to be the flagship of AMD in the desktop processing world. They give amazing multicore performance compared to any intel CPU even close to their price range. Take for exaample, the FX-6300 which beats any i3 in multicore performance and it is cheaper. The FX processors are great for anyone building a mid-range desktop ($500-$800) and allow for a lot of multitasking. They are also favored for editing because the multicore performance greatly improves render times. The lack of integrated graphics, however, means that a discrete graphics card needs to be bought, which is why they are more intended for mid range gaming. Another great aspect of the FX series, is that every processor has an unlocked multiplier, making overclocking extremely easy.
The Comparison
When put side by side, an A10 7700K will beat an FX 6300 or 8320 every time in single core performance. The FX will dominate in multicore performance. It is difficult to trust the CPUBoss comparison, because it takes into account the graphics processing power of the A10 as well, making it look far better. As just a CPU, without graphics, the FX processors are much better, especially with their overclocking potential. As for bottlenecking, high end APU's and lower end FX CPU's do have a tendency to bottleneck higher end cards (anything better than a GTX 970), but for most people, this isn't an issue. Seeing as you have a GTX 960, the ideal CPU would be an FX
6300 or
8320. The FX CPU's are always the best option if you are planing to buy a discrete GPU worth more than $80, otherwise, go with the A10 and stick with the integrated graphics or a low budget GPU.
I believe that you get what you pay for, and between both the A-series and the FX processors, this holds to be fairly true. I hope this answer gives some insight to you, and anyone else who views this thread. Let me know if you have any questions!