I'd want pretty much what we already have (a three-horse slant with a small tack room), but with some add-ons.
- five- or six-horse slant load, with removable partitions
- high ceilings for Dubs
- insulated front tack, with room enough for four saddles/bridles, two driving harnesses, and a mattress.
- lights throughout
- Air Conditioning and heat
- water tanks