Surprisingly the old textbook went to three editions, the last in 1997 [1] It looks as if it may be on archive.org [2], and is definitely in Google Books and LibGen.
> How would you go around building a computer out of commodity components today?
Good question. You could of course retrace my steps using 1980s technology, but I wouldn't advise that. The problem today is physical scale. Most components are surface mount and you really need to build multi layer boards and use a bench microscope to place and solder. Getting anything hand-built to reliably run faster than 100MHz without knowing what you're doing is no fun. Everything I spent a thousand hours building is in a SoC for $1 now.
> Do you think compiling everything on own computer results in noticeable increase in performance?
That's a question to ask Gentoo/Arch users (and BSD people who use Ports). I think yes, because hopefully you'll optimise for the architecture you have. But is is worth it? Given the many hours you'll wait, maybe not at my age :) Do it while you're young and can learn cool things from it.
[1] https://www.goodreads.com/book/show/950048.Microprocessor_Sy...
[2] https://archive.org/details/microprocessor-systems-design-68...