The guy who makes all my gunleather is in the process of stitching up a cover for my steering wheel. It's going to be pricey, but I know the quality will be there
how does it look/feel are the grips molded into the plastic?
Some split grain cowhide would probably be the most durable. Full grain, might be too thick, or difficult, to mold. I'd suggest a saddle shop or geniune cowboy shop. Another option might be a farm supply store.
The best way to get a tight fit, is to soak the leather in water, and install that way.
I'd recommend the wheel be somewhere besides to top of the column, or your electrical system might start growing green stuff. Once it's stitched down snug, wick out as much water as possible with soft towels. Hang it in a warm, shady place, with a slow fan, until cured dry. After fully dried, brush with neatsfoot oil, let soak in, and buff with a clean towel. If/when it starts to appear dry,
When it gets gross, brush with saddle soap, let dry, and re-apply neatsfoot.