[copied fron yesterday's thread where I posted by mistake. I can't cope with age making me a crap runner without advances senility!]
LHM: Althought the HM option looks harder to achieve, at least you can have several attempts at it. You only get a couple of goes at the mara in one season. Champ entry usually closes in Jan, and you can upgrade from a GFA place.
Chicka: you'll be fine. You've done the training and your back has coped. You'll be well rested after the taper madness and you'll fly.
NZC: The UK record holder is Steve Jones. He was also the world record holder. Great runner and Mo's performance shows how good his record was.
LMH: my suggestion would be: miles, miles, & more miles I once gave my all for a PB off 80mpw and couldn't imagine how I could get a champ time. 3 years later and I ran 10 mins quicker off 100mpw. The sub 90 half may be an alternative route.
Chica, I ran Chicago and didn't feel the jet lag had much of an effect. I'd be more worried about the hill