Getting a new PC

What is your monitor resolution?

2600 or 2600x make only difference if you not indented Overclock after OC both are equal.
I have Rx 580 4GB I buy used one for around 130 I used just fine with 1080P Screen 8GB is fine but do not overpay to much :)
Mobo with OC capability if you intend OC B450 will be fine for mild OC

With the 370 chipset you'll need a BIOS update for the 2600 to work. Get the 450.

I have a 580 8Gb and so far I'm in love with it

I plan to buy something similar, so take look at my current state.

I have the 580, and it is wonderful. I have not had problems in any game. I don't play the most demanding games, and I play in 1920 X 1080.

I have run TW3 on it, though. Smooth.

It can't do PhysX, so have to do without a few options on, for instance, Batman Arkham Knight.

AMD launched the RX590 a couple of days ago, it think its around 10 to 30% faster than the 580, and its not more expensive than the 580.

hope this will help ( 1080 gaming pc )
https://www.youtube.com/watch?v=OnrwBA1IzIE

im currently building my PC as well.

these deals leading up to black friday have been amazing,
got an asrock x470 taichi motherboard for $175,
and a phantom 820 (white) computer case for $80. (and somehow they accidently sent me 2 of them i was so shocked when the next day i got a 2nd case at my door lmao, blew my mind)
got a samsung 970 evo 500gb for $75
a EVGA 550 G3 PSU for $60
got a EVGA 1060 6gb GPU for $150.

only thing i have left to buy is CPU and RAM, i plan to do a 2600x and for RAM im waiting for a good sale on Vengence pro RGB 3200 (white version)

like you i spent hours trying to decide on 2600 or 2600x. and honestly im still unsure. cant decide if i wanna overclock the 2600 to turn it into the same as a 2600x. or just get the 2600x and not worry about it

I have a rx 580 4gb for a month now and I'm quite pleased with it. I can play everything on ultra and above 60fps but to be fair I play on a 1024x1080 monitor, I don't know how well it performs on higher resolutions.

If you plan to overclock, get the 2600. If you don't want to overclock, get the 2600X.

RX 580 8GB is great at 1080p, and decent at 1440p in the latest games. Older games will obviously run much better.

The x might be worth it if you don't want to overclock, but if you intend to overclock, just get the standard 2600. As for the RX 580, I have a Sapphire RX 580 Nitro+ 4GB, and I play everything relatively good at 1080p, High settings at the very least. The 8GB performs slightly better and can achieve Ultra more often thanks to more VRAM. If you're looking to save some cash and don't mind a few fps less tho, the RX 570 is probably the better option where bang for the buck is concerned right now, but all depends on region. Lastly, I'd just go for a B450, save some cash, ensure compatibility without BIOS updates, and can overclock good I'm sure, B350's were fine for the previous cpu's.

i d go with rx590

Depending on your location, the price difference between the 2600 and the 2600X can be anywhere from practically zero to over 15%. If you are in the former situation, get the X edition, otherwise, the 2600 is fine. It is not like with Intel, where you need the K edition to overclock (or underclock), you can modify the frequency of both Ryzens by default.

Also, aim get the 450 chipset.

It is a solid build there, all around. You will still need DDR4 RAM (Ryzen loves high frequency modules) and a decent SSD for system though, if you do not have some to move from the previous PC.