From 720p 60 fps so much to say that it’s almost nothing for the components you initially chose.
In my approach I will consider that you want to please yourself, because in practice everything will be oversized but I don’t make any blah blah, I respect your choice
CPU : AMD Ryzen 9 3900X Wraith Prism LED RGB (3.8 GHz / 4.6 GHz) – Due to the number of cores you can stream VERY VERY VERY widely from the X264 with a very very very good preset in 720p 60 fps such as slow. Considering your budget I really hesitated with Intel since we’re talking about gaming and streaming (if you ever wanted to do it in x264). You have to know that it has a much higher cost for a little more performance but finally it’s better to stay with AMD for your Youtube videos and your
Ventirad : be quiet! Dark Rock PRO 4 – Excellent choice, personally I love the design and the quality of the materials. I checked, it’ll fit in your box.
RAM: G.Skill RipJaws 5 Series Black 32 GB (2 x 16 GB) DDR4 3600 MHz CL16 – On budget, let’s make it
GPU : Gigabyte geforce rtx 2080 super gaming oc 8g – The 2080 Ti is a real waste of money, it is designed to play 4K in ULTRA without any concessions. It’s good to have a nice budget but it’s not so good to throw your money out the window, considering what you want to do with it. In theory an RTX 2070 Super would be enough, but if you take the stream component you can go one notch lower with the 2080 Super
Everything else below is very good so I have no reason to dissuade you
CM : ASUS TUF GAMING X570-PLUS (WI-FI)
SSD system : Corsair Force MP600 500GB NAND 3D TLC M.2 2280 PCI-E 4.0 4x NVMe
SSD games : Samsung 860 QVO 2Tb SATA 2.5
Power supply : be quiet! Pure Power 11 700W CM 80PLUS Gold
Fans: 2 x be quiet! Pure Wings 2 140mm High-Speed – Maybe Silent or Shadow Wings are better, Pure Wings are the entry level at be quiet! Even if they’re good at taffing, you could afford to take better.
Box : be quiet! Silent Base 601 (Black)
I don’t know much about peripherals so I’ll let someone advise you on that.