Yep, I did look into the Gates Belt Drive, it is a neat transmission solution, but the fact that the rear chain stay has to split, put me off.
I have been riding a none electric Rohloff bike since 2004, and my plan is to make it electric (Bafang 8fun CD).
The gear shifter numbers have worn of, and if I am honest, this is better in a physiological way, as I just ride in the gear that suits me best.
You can get a third party electric gear changer for the Rohloff, but I don't even see the point of such an item.
At the time (2004) I built my Rohloff, I bought 6 of the SLT-99 Chains, I think they are 7 speed, maybe 8, but at the time were well out of fashion for Derailure riders, so I got them for around £25 each.
I have only gone through 2 chains, so far, just a pity that a Rohloff stopped making them a few years back, although at my rate I will be past 80 when I am on my last chain, also bought a litre each of the Hub Oil and Rinsing Oil at the same time, which is enough Rohloff Oil to see me out!
I have been using a Brooks Swift saddle since the get go, but if I was ever to change it would be for a Gilles Berthoud saddle, very similiar to the Brooks, but a much better engineered finish it has to be said.