Memory cards, definitely, but how is finding one on 3.60 a downside? You can buy any new Vita sans 2 recent colors from JP and it's guaranteed to be on 3.60 or lower, PSTV included. Even most used/"refurbished" ones in stores will be on <3.60 if the stock is old enough (which, lets be honest, probably is). eBay is probably the only place where you run the highest risk of getting a 3.61+ Vita, but even then you'll probably find more on 3.60 since Henkaku became wide-spread.
Yeah, I would purchase new to avoid this, but finding a new vita here on shelves is impossible.
People who don't know about homebrew/hacks/backups are going to be on latest firmware, and unfortunately people who know are trying to sell 3.60 systems at a price premium =(