Solid state drive much better idea, more reliable in long term.
Flash is basically the worst for cold storage of data. JEDEC specs for an SSD only specify retention for a year without power. You'd be better off using an HDD at that rate. Or you could use archival quality BD-ROMs. You should be able to get a couple of decades out of them.
That's assuming the use case IS archiving. The thread seems to be going that way but it's not clear from the OP. But relying on flash long-term is risky and it's definitely not an archiving medium.
