As for the unboosted maguras, shouldn't be as much an issue on the rear? as most of the big handfuls of stop are at the front wheel and it doesnt take much pressure to lock a back wheel.

I'm also on the lookout for a suitable bike rack, there are loads of trails between here and Manchester I have a great one that crosses saddleworth moor near the mast which could easily become the meeting/starting point and theres even a good pub en route although its just before a rather knarly DH.