Not much branded accommodation, but a LOT of B&Bs and small hotels along that coast. Check Hunstanton, Brancaster, Wells-next-the-sea. And some good campsites, as well as the actual event one they are setting up. Certainly a good location if you have a family to keep interested - sandy beaches within walking distance of the start, and a fair amount of other tourist stuff along the coast if you want to make a weekend of it.
As far as I'm aware, there's no Ford Capri in the lake, though. That may count against it!
Outlaw was my first (and only so far) Iron distance, so I'll +1 that as well. I ended up shuffling (you couldn't call it a run) the first half of the marathon and alternating shuffle and walk for the second, but it was the first time I'd attempted a run over 13 miles. So you certainly don't need to be a trained marathon runner just to finish. I'm hoping to do a bit better next year!
I'd take run training slow and ramp it up as the weight comes off - its probably the easiest way of injuring yourself, and that drops you back into the I'm-injured-so-I-can't-exercise-so-I'm-putting-on-weight-again cycle. As Cougie says, if you're within range of Nottingham come and volunteer in the summer and you'll learn a lot about what goes on - I certainly wish I had.