From what I can tell, the "heroID" printing is authentic. It doesn't seem like they have Euro sleeve patches for it, though, if you were looking for that as well.
I haven't heard of a lot of issues with them not having stock, but I personally had an issue of being charged for something that hadn't shipped and apparently was not in stock. They refunded me right when I asked about it without any problem though.
Yeah so I recommend emailing just to double check on the stock, and might as well double check on the official Germany printing as well. But it seems like neither of those will be an issue in this case.
Definitely worth a shot, cuz it doesn't seem like any other reputable places have it, and it's only around $80 total, so worst case scenario you don't lose out on as much as you normally would getting a printed jersey from overseas.