Great idea, but towers will soon be obsolete. Now days a generic whitebox as they used to be called is no cheaper than a laptop. The only people still building are Miners, Gamers and maybe some old school media tanks.

I used to read my copy of "upgrading and repairing PC's" by Scott Mueller
for this type of info.

https://books.google.com.au/books/about/Upgrading_and_Repairing_PCs.html?id=E1p2FDL7P5QC&redir_esc=y