WTB: 512GB/1TB m.2 nvme gen 4 ssd

I’m planning to dual boot my laptop and wish to keep both isolated as much as possible. My laptop does have an empty gen 4 slot.
For this purpose, I’m looking to buy a m.2 nvme gen 4 ssd, prefereably 512GB. 1Tb works too.
Any leads for new or used ssds would be appreciated.

Thanks