I use 32/19 on a 29er Inbred, a good compromise I find. The frame is great, it’s the one with horizontal dropouts and a gear hanger, in case I ever want to run t geared. I haven’t found I need a tugnut, a decent Shimano XT QR holds the wheel plenty tight enough.
A few things that echo what others have said:
1. A normal cassette hub with spacers is fine – and allows you to change to geared if you ever want to.
2. Get a decent cog when you decide what ratio you’re going to go for, I have a Stainless Velo Solo one that is showing no signs of wear even after 3 years.
3. Don’t buy the On One tugnut if you decide you need one, it doesn’t actually fit/work with the Inbred.