Like some of the others stated, if you can wait until after Jan for the AMD 3k series chips and GPU's are shown then I would suggest going for that. However if timing is an issue, even the non X model 2600 or 2700 will run anything on today's market, with a good GPU on ultra without any issues. I upgraded not to long ago from a FX-8350 to a Ryzen 2600 / GTX 1070 combo and couldn't be happier. I have a 1080p gaming monitor at 75Mhz so as of today, nearly all modern games are hitting my monitors cap at 75 fps including Star Citizen (although due to game still being developed, those FPS range from 30 to 75).
I use a SSD for star citizen (western digital blue SSD 500gb) and the load times and play stay of SC was a drastic difference compared to running it on a HDD 7200rpm drive. I have a thread I created in Spectrum showing the load times with the HDD compared to the SSD. From 4 minutes to 30 seconds :)
https://robertsspaceindustries.com/spectrum/community/SC/forum/50174/thread/ssd-load-times-compared-to-hdd
16gb of ram will do for now. However I would suggest since you have a high budget, to go for 32gb. And Ryzen likes higher speed on RAM, so don't go any lower than DDR4-3000 for ram speed.
As for the hard drives and SSD's, I've always been partial to Western Digital as I've never had any to fail or cause me issues in the past. I've got 22 years in the IT industry and never had an issue with WD. Toshiba and Seagate drives have failed me in the past.
Motherboards, there is not a lot of usable difference between the B450 and X470 boards. To save on money and since you are using this mainly for gaming, I'd suggest the MSI B450 Pro Carbon Gaming motherboard or MSI B450 Tomahawk. I'm using the Tomahawk board and no issues here with the Ryzen 2600. This has been a good budget minded gaming rig for me. And still able to handle some development work that I do. And my only reason for going 2600 instead of the 2600x or 2700x was the power usage. I run my system 16+ hours a day. And honestly there is no games out there today that would require you to overclock the 2600 or 2700 non-x models paired with a GTX 1070 for good gaming on ultra settings for 1080p or 1440p gaming. Although I do believe the 1070 is reaching a struggling point on some modern titles at 2k gaming at least from some reviews I've read. Haven't tested myself however due to well...my current monitor lol.
Good luck to your build, all in all, can't go wrong with either 2600 or 2700 processor route and you shouldn't really spend more than half of what your budget is. So you will be able to save some $$ in the bank, use for other needs. :)