Worlds Toughest Mudder

Has anyone done this before??
We're heading over with 2 nutters that thought this would be 'fun', they've put the training in and they're aiming to complete 55miles in the 24hrs.
Any advice for us, what are facilities like, what's the minimum amount of water you would take (we're taking bottled water, as we're from the UK, the difference in water is likely to upset stomachs), we're looking to buy a tent etc once we arrive but what else should be be thinking about.
We've done endurance obstacle runs before, but it was 20 miles in 3.5hrs, rather than a 24hr event where over 12hrs of it will be in the dark (are head torches necessary or do they have the course lit up)??