I'm using 6 3600 for mining RTM ,BTRM ,EPIC SET 1.082 v at 4100mhz I have a ID se224 cooler 2fans at 48deg C AMD 5600X I use Scythe fuma2 Amd 5900x Noctua NGH-D15 I had similar problems until I set voltage and frequency in bios or Rizen Master Also testing shows very small hashrate gains above 4100mhz not worth the power or heat
ID-COOLING SE-224-XT Black CPU... https://www.amazon.com/dp/B08BY9P911?ref=ppx_pop_mob_ap_share
JSEcoin - can be integrated in websites to replace web banners and monetize content (main purpouse). Also, can be mined via browser on their website (CPU only).
Coinimp - Mine Monero via browser, can also be used for monetizing content.
They are both ask for permission the visitor before activating website mining.
If you decide to just mine on your own, the PC barely feels it. It's very adaptive.
What's your budget?
MSI Performance Gaming AMD X470 Ryzen 2ND and 3rd Gen AM4 DDR4 DVI HDMI Onboard Graphics CFX ATX Motherboard (X470 GAMING PLUS Max) https://www.amazon.com/dp/B07Y468HV3/ref=cm_sw_r_cp_apan_glt_fabc_C6XCTHZRWAQ83RCFNDRB
This is $100, it's a bit more than you really need, but it'll handle the power for the Processor a little better than a 50 tier. The 400 series is older but it'll handle a 3900 just fine.