This is a decision you'll likely only be confident making after you've been on the road for at least a few days. Everyone is different and your preference for handlebar style depends on your riding style, terrain, etc. That being said, I think that high, flat handlebars are going to be the most universally friendly. Perhaps it'd be wise to start with flats and refine your preference from there.
I've put several thousand miles on my touring rig that has drops, but to be honest, I find myself only riding the drops when up against a nasty headwind or when I just need to mix it up a little to avoid soreness. In both those cases, they are helpful. Otherwise, I ride almost exclusively on the hoods.