Question Question: Building budget PC for my bro: Will there be any problem with these components fitting together? Component replacement suggestions welcome.

Lordvile is right. Although it's a budget PC, you might want to be able to upgrade it at some point but AMD moved to their AM5 platform a few years ago so going with AM4 for a new built is not a really good choice. Same for the PSU. Getting more power headroom for future upgrades will save you money and time in the long term.

Just a very quick search and I found a B650 Gigabyte motherboard - Ryzen 7600x CPU - 32 GB Patriot RAM kit in a 360$ combo on Newegg. Combine that with a 650 or even 750 W PSU and you gonna be in good shape for a few years with plenty of upgrade options.