I would agree with Alms there. 2070 isn’t going to cut it if you are looking to be serious about 4k gaming. You would mostly be fine at 2k and some older and less demanding games could do 4k, but if you really want to be comfortable at pushing 4k 60fps with the majority of games, you really do only have one option; the very expensive 2080ti. Even my 2080 Super, the one below that, won’t give me 4k with most games.
If you can bare waiting a couple of months though, the new Nvidia cards are coming. From the sounds of things, they might be offering reasonable 4k gaming at a cheaper price (but still not very cheap).
Should also add, the 3600 is probably okay, if you are just gaming. You might get some noticeable improvments with a more expensive Ryzen, but only minor. The GPU should be the focus.