Hi,
It depends on you and how you load the bike. I personally like a very large range of gears, but everybody has their own taste. As much as possible, find a bike that is geared how you are considering and take it up one of those mountains loaded how you expect to be loaded.
If you do end up going with a 1x10, I'd probably recommend making sure that you have the lower end you want (and you'll end up coasting down the big hills).
Cheers,
Charles