After having had another skim of the Malifaux rules book, I've been contemplating the Wild West.
Some time ago I built a 6'x4' table for Legends of the West, GW Historical Gunfighter rule set. It's pretty impressive, even by my standards of the day. I have a railroad that runs through the centre of the table (4' long) and there is an expansion that includes a fort (who can say F-Troop!).
Now I just have to venture into the shed, avoid the Red Backs, jump when I hear reptilian noises and hope that it's not at the very back.