In reply to tony:
If its dry I'd be tempted for a road or cushioned trail shoe.. its gravelly sandy trails for much of it then hard rock and scree for a short section over the bealach.
NotaClue: I'd consider something with grip then, but that's more of a fell race than a trail race, 3000m of ascent in 80km is a big amount, in the alps you can do that by zig zags but in the UK the paths are more direct generally..
You've got everything on that but a fair amount of proper fell terrain, especially if its wet, which it's October in the lakes.. It depends on the trails, the lakeland 50 route is very much trail running and I've ran most sections of that in road shoes, especially if its dry they are fine.. but this route is much higher level fell/trail running.
The main thing though is comfort, but you'll want grip and also some cushioning. I wore the x-talons for a traily mountain race in Slovenia and whilst comfy in general my soles took a battering on the rockier sections.
have you tried the speedcross? Not worn the fell raiser so can't comment but they look similar, the profiles are different. I love the speedcross but the high heel provides issues for some people.
Either those or the roclites would be OK but the fit is the biggest issue by far.