Step 1. Follow this and use PGP for communications.
Step 2. ???
Step 3. Profit
Voila, now we're on a decentralized marketplace and aren't left fearing the next beard competition,honeypot,"server update" shitty market.
Edit: Since tails being left out was mentioned figured I'd address that. People take tails to be the holy grail of security even though the only thing it really has going for it is the amnesiac angle. I suggest people research the alternatives, specifically Qubes (OS based on the idea that every window you open is its own virtual machine, essentially) + Whonix running within that + TOR inside of that. This entire system can be loaded (granted, it is a bit more hands-on) onto a live usb in the same fashion tails can.
Show me where the vendors are and I'll pop in. You're talking to the wrong people.