KO______ the having data part is easy enough from the SIM card hawkers at the airport. Might not be accepted by a bank, or entirely secure
the big headache for me is trying to keep dollars in mint condition. The exchanges can be picky, especially the ones with good rates. There doesn't seem to be a commercially-made, dollar-sized hard case that can do it. There are flimsy plastic sleeves and storage cases from the numismatic industry, but not really good enough. I ended up using cases cell phone screen protectors were shipped in