Hi Grant, welcome to the forums!

I would opt of a speed hub for my touring bike if i had the cash, the benefits area great, but with such great highs, there has to be a down side. In this case, the downside would be possible failure. Nobody but Rohloff will service the hub due the the complex nature. If it fails, or one of the internal gears shears off, the hub is useless. With a traditional drive train you can limp out of any situation. The speed hub should last you, but there is always that small chance of things going wrong and you pushing the bike to the next town.

As for gearing, the chainring size doesn't help without knowing what size sprocket you are going to run. I'll assume the 16 tooth OEM sprocket? If that is the case a 46 tooth cog is geared very high. You are going to want something you can ride up mtns, and coast down the hills with. I would opt for a much smaller chain ring
46 sounds way to big for touring.

Maybe one of the other members can give you a gear range to target, then you can see what chain-ring / cog combinations will work for your setup.