Welcome to the forum,
I've been doing some research for you on this one. The amazon jersey is not an official jersey as far as I can tell. As for the autograph, I can't help you with that one, I'd be happier with a JSA COA. i've not heard of 'all about autographs', so I cannot comment.
eBay has a few, mainly fakes. This one is a vintage Champion jersey, no fakes back then, 380349764797.
This one is a Mitchell and Ness jersey , from a genuine seller, sultan of sports. 190562313540
Can't go wrong with a genuine M&N jersey, very accurate.
Good luck.