RAM is very important, you have to buy both RAM sticks at the same time.
Using only 1 RAM stick will cripple the system and you'll lose up to ~25% of the actual performance.
1 large SSD is enough.
Crucial MX500
Samsung SSD 860 EVO
Each as either 500GB or 1TB version.
My PC has a very old Crucial MX200 model which has only 2D-NAND MLC instead of 3D-NAND TLC and over the years has gotten a lot of read/write abuse (as my old PC only had 4GB RAM, so the missing RAM got allocated onto the SSD) and it is still in perfect condition, ~99-100% lifespan remaining.
So yes, they are reliable, if you go for the good models.
Whichever you can get cheaper. Get the regular 2.5" SATA modell.
M.2 as NVMe-SSD is only noticable when you do 4k video editing.
Using raid is soooo year 2000, so don't do that.
1 large SSD (1TB) for your OS and games.
1 very large HDD (4TB+) as data grave and if you want to record footage onto your PC.
If the R5 3600 is within your budget, make sure the B450/X470 board is the "MAX" model, otherwise it won't boot up and will require a BIOS update beforehand.
Otherwise, with the 2600 you can just go for a regular B450 board.
"MSI B450 Tomahawk Max" is a good buy.
The RX 570 8GB is a good entry level card, nowadays it's no longer mid-end.
It will get you a minimum of 60 FPS on every game (except a handfull) in FullHD with max graphics settings (no AA).
Streaming with it is no problem, it can support a stream/record video (OBS) output up to 1920x1080px/60fps/40000bitrate on the balanced setting of OBS with no loss of FPS.
Though on Twitch you are limited to 6000, so it's better to stream with a 720p output and YouTube it's not really worth it to go over 10000.
If you want to record gaming footage onto your computer with OBS, stay with 30000, that's what I use, to preserve as much quality before the video editing compression and YouTubes additional compression.
https://www.youtube.com/watch?v=UcIAn1vKOM0&t=5m
(recorded with an RX 580)
For mid-end cards you'd have to look for:
Vega 56
Vega 64
RX 5700
GTX 1070 (Ti)
GTX 1080
RTX 2060
RTX 2070
They are all roughly within the same performance.
Vega 56 is equal/better to GTX 1070, RTX 2060
Vega 64 and RX 5700 are equal/better to GTX 1070 Ti, GTX 1080, RTX 2070
My recommendation would be to go for an AMD card.
Either the RX 570 8GB or the Vega 56 if you can find one cheap.
Best buy would be the RX 5700 as Sapphire Pulse model.
For the Vega 56/64/RX 5700 you should get a 650 Watts PSU though.
Seasonic Focus Plus
Corsair RMx Series
be quiet! Pure Power 10
be quiet! Straight Power 11
Are good models.
