What Shoes for Snowdon

Hello 

Last year on a whim I entered the Snowdon Marathon, and while it won'tbe my first marathon or first race that has a lot of hills, it will be my first that is a mixture of road and off road. 

i was wondering from anyone who has enetered in the past can reconmend what type of shoe I should run in. Will a basic running shoe, or road show do? Or should I be looking at buying a trail shoe or even a hybrid??

According to there website and repoets some of the race does go off road and onto trail and being that the race is at the end of October, it is always possible that it could be wet or even icy. How off road I do not know. I run in a road show on the canal paths and some of the walkers paths in the peaks and have no issues but are the paths on the marathon likly to more 'trail heavy' than friendly walking routes. 

I know it's a bit if a silly question but i don;t want to get to the race after months of training to find i am having to walk most of the course becasue of incorrect footware. 

thanks in Advanced.