I can't help about
Amin...
As for the other, I've just check my extended family tree, and there's no one with that name, be it in
Israel or in Diasporah, nowadays or 500 years ago... Imo
Amon wasn't a very good or very important king, so it may explain why the name isn't used, just like I dunno...
Dathan for example.
Moreover
Amon is an Egyptian deity and most Jews wouldn't want their kids associated with it.
Check:
http://www.reference-guides.com/isbe/A/AMON/http://www.infoplease.com/ce6/people/A0803782.htmlI hope it helps!