The people have spoken - the start will be Northallerton.
I'll update the OP. Let me know if you're planning to attend, wavering, or defintely can't come.
I'll have to think about a route - I'm assuming everyone is happy with no more than 60 miles, at least one sheltered overnight stop with coffee and toilets and stuff, and some hills in the second half (can't really do much about the latter).