In reply to PeteBott:
I've run two ultras plus a load of ultra trainings in Sportiva Bushidos, a lot of the time over the same paths you'll be running on the OCC. You see an awful lot of Bushidos here, they are a great shoe for the terrain, and that distance. I'll be wearing mine for a race in June, using some of the same paths as your OCC.
If I'm honest though, I bought them because they were 40% off, and I had to cope with about 100km of my slightly-wider feet naturally pressing them out a bit. Once the foot got the fit though, I haven't got a bad word to say about them, and I'm tempted to replace them straight off when they die (if I can find them reduced again, that is).