Definitely get a full rack of spare ribs and cut them down to a St. Louis style rib yourself, that way you can have the rib tips as a greasy yummy snack while waiting for the ribs to finish.
Don't hold off on the pork butt, they're easy and you should give them a run. They do take a while to cook and EVERYONE has a different idea of how to cook it. I suggest you use a bone-in shoulder, I think they come off of the smoker with a better pork flavor and seem to hold their moisture much better at a higher temperature.
Here is a good article about wrapping and temperature rise in smoked meat.....talks about how basting isn't all it's cracked up to be.