For Blender 1700x should be better. (more cores)
For gaming 2600 should be better. (faster cores)
Yes, looking at the 1700 and 1700xs price, it is hard to pick between those or 2600/2600x.
Here where I live:
2600 = €169
2600X = €210
1700 = €200
1700X = €220
I for myself would pick 2600. The cores are about 6% faster (you can also OC it) and it still comes with 6 cores 12 threads, which should be already good enough for most of daily rendering, unless you are a pro-renderer, who renders really a lot
If you renders alot, and I mean really, a lot more..I would rather grab TR 1920X.