I was going to post pretty much what MadMatt said. For gaming, you might not see much benefit from those two extra cores any time soon, so the 6 core, 12 thread 2600X would probably be better, and should slightly outperform a 1700X in most games due to its higher clocks. The vast majority of today's games are still designed to run well on quad-core processors, after all, and it will probably be some time before games fully utilize a 6-core processor with SMT, let alone an 8-core. The 2700X can manage slightly higher boost clocks than the 2600X, but that won't make a very significant difference in games for a 50% higher price.
And for Ryzen, it's generally best to go with higher speed RAM, so ideally you might want to look for some in the DDR4-2933 to 3200 range, which shouldn't cost much more.