Clock speeds don't make TOO much of a difference, though I'd get a Ryzen 5 1600X that can OC to about 4 ghz with an ASRock AB350 Pro 4 or ASUS b350 Plus mobo
You could go Ryzen 2nd gen, though it's only a 3% performance increase and generally not worth it because of the high priced X470 mobo's.
Remember, with Ryzen, faster memory is a must. 2666 mhz at minimum, though I do suggest 3000mhz 16 gigs DDR4 memory to be the best.
Good luck with the build! Keep in mind the July 4th sale is coming soon so you may wanna pounce on that if you see any good sales.
Chat about almost anything as long as it is within the rules.