Way
It's not how you do it.
You create a company that specialises in processing data, especially medical records.
Build some reputation over the years.
Start lobbying politicians and people responsible for tenders.
Get a contract from department of health or something for processing medical records.
Make sure your lawyers sneak in terms that will allow you to choose subcontractors to process data virtually unrestricted.
Now you got the medical records, they pay you for having them and nobody calls you a thief.
Then instead of advertising on darknet, advertise that you look for subcontractors on the pedestrian web.
Hire them to do processing they want to do while they pay you to your completely unconnected offshore vehicle.