No, it will not cause a bottleneck at all, it is still a good performing CPU.
Your GTX 970 will be overclockable regardless of the motherboard you are using. Your PSU might be of influence of being able to run a GTX 970 and overclocking it, you will need a PSU that can feed at leats 28 amps on the 12 volt line, in general a good 500 watt PSU will do.