Didn't you ask the same question last year?
What's changed, oh yes, the Nomad. From Thorns range, that's what I'd probably go for, with 650B wheels.
Maybe I shouldn't say this here, but Thorn don't make a dedicated gravel style bike, if that's what I was looking for I'd probably look elsewhere. If what you want is a 50 mile blast, then a bike designed to go round the World is probably the wrong thing.