Rohloff , the already World Touring tested 14 speed Internal Gear Hub, and whatever single chainring crank you choose..

My choice: was a Shimano XT M730 crank. I got in the 90s, a Surly Stainless steel Chainring and a Black anodized disc Chainring guard.

& a Whipperman Full-bushing 3/16" wide Chain.

but the many Popular derailleur index shifting drivetrain people have a different Opinion . Best is just that, .. an opinion.