Where is the best place to get a cat?

Either way, they're both stray cats more or less. If you don't get the cats from your friend its possible they might wind up in a shelter anyhow. Normally I would say get your pets from a shelter, but the one thing I would worry about is that those cats are more likely to have come in contact with other cats there that are sick. I volunteer sometimes at a local shelter, and they keep the sick cats contained in their own rooms, but it still makes me uncomfortable thinking that there may be some cross contamination along the line.