Any full grain leather will do the job and hold up well the surface will age with time and use picking up a lot of character. I suggest you seek out a leatherworker, Etsy has a bunch, such a thing isn't particularly expensive and will outlast you if cared for, you can get one custom fitted to match any insert you like.

I quite like the Midori/Traveller style myself if you talk to a craftsperson you can get something to suit your taste.