Fat bikes and pannier racks
Many of the expedition/endurance race fat bikes will come with rack mounts.  If you plan on "packratting" and carrying groceries, you should avoid the seatpost only options.  They generally have low weight restrictions and can also have issues with the bags flopping into your wheels (they are often missing the side panels regular pannier racks have). 

If you look around a bit more, it should be fairly easy to find fat bike companies making rigs that are rack ready.  At most of the winter endurance races, racks and sometimes panniers are common.  The Surly Pugsley (the original production fatbike) still comes with rack mounts (rear AND front).