I'd suggest at least UHS 1, which is also a class 10. Meets class 10 minimum requirements and boosts them up a bit.
I picked up a nice 64GB UHS 1 / Class 10 by SanDisk, and I'm getting 18MB/s write speeds and 45MB/s read speeds. Speeds will differ. If the packaging or write-up doesn't brag about the speeds and name what they are, then it probably is going to be the slowest that qualifies for that class card, and I'd pass on it.
Of course, I won't be doing anything like that right now, just prepping for the future. Still have a low end device for now, but only because I was going to "test the waters" with a WP before I jumped in with both feet AND my wallet. I'm happy enough I'll be getting higher end soon, I'm sure, so the fast SD was good investment.