BUY a legal set of ROMs and legal copy of Amiga OS 3.1 from any seller of your choice.
No one can claim to be a supporter of any platform if all they do is steal software to run on old hardware.
Every pirated copy being used is a little money that SHOULD have gone to the copyright owners and resellers to encourage them to stay in the business of improving Amigas.
Pirates steal from all of us.