John: with respect to the level of fitness, yes, its taxing, but that's what I kinda asked for. I have sent them a client who was fit, but couldn't do the lots of vertical meters (due to major knee surgery 1.5 years before), and he was OK with it. The great thing about this place is the guides set the pace you can handle. The year before I was in a crap state, and flu to boot, and the pace was a lot easier going.
I would suggest getting in touch with them (PM me for details if you want) and discussing it with Dani. Sure it could be made to work.