I've had a couple Rohloffs and a couple LHTs, but never combined them.

You'll need to run a chain tensioner since the LHTs dropouts are vertical.

If you get the disc trucker you can run a Monkey Bone and the OEM 2 Axle plate to stop the IGH from rotating as you pedal. That's a reasonably clean setup.

If you have a rim brake trucker you'll need to use the Rohloff long torque arm. Frankly with that and the tensioner it's a pretty ugly setup.

If you are set on a Rohloff and open to another frame consider getting one that has some sort of chain tensioning mechanism built in [EBB, sliding/swinging dropouts, etc...] and disc brakes. You can have a really clean/simple setup that way.

Given the cost/investment in using a Rohloff I'd get a frame that works really well with it vs. hacking a frame that isn't well suited to one.