I'm a fan of Rohloffs [I've got two] and one would definitely give you the gear range you need with a single chainring, but honestly if you are going to add a $1500 hub to your NWT I'd sell the current one and get BF to build you a Rohloff specific NWT. You'll be a lot happier in the long run.
Vik, is the Rohloff really a perfect solution? That is, if I will take the plunge, am I 'guaranteed' to have long lasting perfect shifting with virtually zero maintenance?
Any down side other than the price?
Thanks,
Kam