I used chrome-tan suede from an old welding-apron on the last wheel I covered. Worked a treat, and after a few seasons of salt, it's hard and rough- nice to grip when it's lumpy and wet, and not at all slimy in the rain. Chafe-protection: wet rawhide- pulls tight when it dries. For spreader-ends and things- just use ordinary tanned leather, fitted wet and tooled to shape with finger-pressure...
We have bought from Boatleather.com in the past and were very happy. Website HERE If you don't want to order from USA, a few sailmaker lofts in UK will supply leather covering bits and pieces but I have no experience of them.
When we ordered from boatleather we decided to go the kit that has a 'soft feel' neoprene under the leather. We have not regretted it for a moment.
No connections with the company except as a satisfied customer.
For making anti chafe patches etc suggest you use chrome leather, available from sailmakers.
For the wheel, I have just bought a kit from Calibra Marine in Burseldon. It is suede finish, holes already drilled and comes with needle, yarn and instructions. Not sure I would like to make one from scratch.
Try a local saddlers as a supplier or to do the work. I had our 28 inch S/S wheel trimmed in grey chrome leather for £50 quid last year. Excellent job as well. Saddlers just outside Plymouth so not local to you unfortunately.