WeeWilly, I agree with you, in the Smokette, two Weber rib racks is the way to go, but remember each rack will need to be cut in half to fit so your total racks will be halved making it about four racks, five at most, without touching.
The number of racks in the smoker is what made my decision to buy the model 55. I have hung six spareribs racks (all without touching each other or the sides of the smoker and feed 10 people. I could have hung one more rack, but they come in packages of three from Sams. Also, keep in mind that sparerib racks are much larger than St. Louis racks and sparerib racks in the Smokette may need the flank part seperated if using two shelves and that will call for more rack room.
We ate some left over ribs (frozen) last night and heated up on the gas grill - they were just as good as fresh and even a little smokier.