More ram will only help you if you are running out of ram. So if you are using a total of 23gb of ram, having 32gb vs 64gb wont make a difference. Faster ram will give you better performance assuming you arent using more than 32gb of ram.
Pretty sure games currently arent using more than 32gb so I would go with the faster ram, and if you end up needing more in the future you can always add another kit to get you to 64gb.