I have not done that particular event, but I could suggest a number of good entry ultras around May/June. The Northants Shires and Spires was my first ultra, as it was for many on this site. The Dukeries ultra is also a nice little number. Other people speak highly of the Dartmoor Discovery ultra, though I have not personally done it!
Edited: 14/10/2012 at 20:27