Bottles are easy to find. I homebrew my own ginger ale and use Grolsch-style sealing caps to withstand the pressure. Buy them on Amazon.

Perrier bottles can be emptied and resealed. I didn't see anything in the article about carbonation.

Depends what I’m bottling and if it needs to be shelf stable. There’s actually just as much work in the packaging of a beverage as the product sometimes.