I'd have a discussion about why they picked a class C. If the budget is sizeable, there's lots of options.
Again... don't know the extent of the handicap, but a class C, class A option generally requires a dizzying amount of upkeep and maintenance... think "boat".
Is there a reason a LARGE class B is not an option? They do lack the space of an A or C, but can be highly modified from scratch. Space can be allocated where needed.
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