This is why I was asking if it's just "easier" to setup a full node and do this with Core?
Really appreciate it everyone, thanks very much!
You don't need to use wget. Just download both the.asc and the .tar.gz file to a directory, navigate from the terminal to that directory and validate it as stated in the post.
Bitcoin Core uses sha256 signatures in a PGP signed message for validation. Probably would be roughly the same complexity, if you aren't familiar with it. The only downside of Bitcoin Core is that you'll have to download and verify the entire blockchain which can take a very long time. Would you be fine with that?