I want to download the blockchain so that I have independence from remote nodes. Because I want to use tails OS , I'd like to keep all data on the USB-Stick. ( booting live with persistence)
Can this be accomplished with a large USB-Stick, and decent write speed? Current blockchain size is about 73GB. I just want to make sure this is possible, before I buy a USB stick with large capacity.
Can this be accomplished with a large USB-Stick
Yes.
...and decent write speed?
Define "decent". USB 3.1 gen 2 is pretty fast. There are loads of USB drives on the market so you'll need to research carefully which you get.
Current blockchain size is about 73GB...
No, it's more like ~90 GB unpruned and more like ~30 GB pruned. Hence you can focus your attention on speed rather than size. For example, 64 GB will be fine for the foreseeable future if you run a pruned node.
