What do you want me to do? You already got the parts and the choices are not ideal, to put it mildly.

Amazon tends to be expensive.
Well you might have to pay for shipping multiple times, but the difference can be big enough to make it worth it. Not every part from a different shop, just 2 or 3 different shops.
Could you try to be a bit more specific than "EU"? The EU consists of multiple countries and not all shops ship to all of them and/or shipping rates are different.

Just FYI there's cheaper RAM, even with the timings you're going for. Also better/cheaper PSUs.
The stock cooler is quite good too, I don't think you'll even need another one.
https://pcpartpicker.com/list/BDv3vV

What do you mean upgrade?
Did you already buy the parts? I thought you wanted to build next month.
Or do you mean improve the part list?

Same in the first post, you wrote you bought them, but you want to build next month.
I'm getting the feeling that something is getting lost in translation.
Bring me the Swedish intern!

That was directed at #8.
Name 5 current games.

Have you benchmarked it? I did.

You do know that especially in TF2 an i5 or i7 is exactly as fast as an i3 with the same clockrate?

#1
This is not customization, this is hardware.
http://www.teamfortress.tv/forum/11/hardware
http://www.teamfortress.tv/12714/pc-build-thread

I don't recommend low end mobos. Getting the cheapest one is usually something you'll regret later.
Caviar what, SATA what? 90% of WD HDDs are Caviar something and all consumer HDDs are SATA [version]. This could be literally anything.
Ignore brand names for RAM. Only capacity, speed, timings (CL14 for example) and sometimes voltage matter. If those are the same get whatever is cheapest.
The 6100 is 2 years old. There's newer, faster options at the same price and one with the exact same speed at a lower price.

The RX 470 is around the same price and much faster.
That's a 200W build, what are you trying to do?

Also what is your budget?

#3
Ignore RAM brand names.

#4
The G4620 is not overclockable.

I'm not sure what kind of budget he's on since he wants to spend more money on the PSU than on the CPU or GPU.

So basically what always happens when you go above 3 brits, happened.

Well the 3.5 GHz are nice and all, but the big thing is that since Kaby Lake the Pentiums also come with Hyperthreading, meaning you get 4 threads. Due to TF2 being weird that is the highest useful number of cores/threads. Meaning a 3.5 GHz Pentium is now exactly like a 3.5 GHz i3 and performs exactly like a ~3.5 GHz i5 (i5-7400, 182$) or even i7 (i7-7700 is higher clocked though, i3-7350K would be as fast though).

So yes, for TF2 it's pretty good.

Bulldozer / new FX series CPU have always been shit for anything that needs good single threaded performance (e.g. TF2) and since they are now 5 years old they have no chance anymore even multithreaded, where they used to be at least somewhat competitive.

Because how is anyone supposed to care about your 200$ mechanical keyboard if no one can hear it?

"I have never fallen to my death in fallout before"
Even Sideshow is in denial and can't believe he was that stupid.
Yes let's all pretend this never happened.
https://clips.twitch.tv/CredulousCrepuscularPresidentNinjaGrumpy
It's less painful that way.

EDIT: Oh my god it got worse. The mines.
https://clips.twitch.tv/PowerfulRefinedPartridgeCmonBruh

Even single threaded where the additional cores don't matter similar frequency with ~50% higher IPC should be noticable.

If the 1800X can run at 4.0 then so can the other CPUs. Same chip.
They are generally supposed to last >10 years and you're replacing your current CPU after "just" 5 years. I wouldn't be worried. Also if you don't go crazy with the voltage it won't fail, it'd just require another voltage bump a few years down the line to keep the oc stable.

Streaming/encoding. Twice the cores. What do you think will happen? Of course it's going to be a lot better.

In 2 months the 6 cores should be released then you can have your cake and eat it too. Cheaper than a 7700, but faster.
Unless you have a really good reason to cheap out and get an A320 mobo, you'd be able to overclock later anyway. I'd recommend getting the cheapest 6 core and then just oc'ing it to 4.0 GHz. Zen runs at a wall there, but up to that even the stock cooler is sufficient. Seems pretty good to me. Overclocking isn't that difficult (see #2209).

It's really just the RAM/latency thing and lower performance than it should get when SMT isn't useful because the windows february patch day got canceled. Windows should get fixed with the march patch day next week or so.
I don't know about any compatibility issues. Not sure what problems you are expecting.

#2209
I was almost worried it didn't work. ;-)
You mean GPU overclocking, right? Otherwise this would've been the absolute perfect post at the perfect time to convince #2208 to overclock Zen.

http://www.teamfortress.tv/12714/pc-build-thread

Definitely CPU upgrade, GPU is good enough for TF2.

You will also need a new mobo. AM3 is dead. If you decide to buy a 5 years old CPU (83xx) you absolutely deserve the terrible performance you'll get (well not worse than now, just exactly the same).

Also DDR3 is dead. So you new need RAM as well.

If you just want more fps in TF2 get an i3-7100 or better.

For streaming an i5 probably won't cut it. You can't really afford an i7 + mobo + RAM, unless you're willing to buy used or get an older one to be able to keep your RAM.

New AMD CPUs are a thing now, so if you can wait a bit you can probably get a 6 core with SMT + mobo + RAM for <=400$, but you would definitely be able to get a 4 core with SMT. That should allow you to stream comfortably.