Glad you got the smoker in time for the weekend, Randy. With regard to rub, what flavor profile (sweet, spicy, Asian, salt/pepper, etc.) are you looking for?
As someone who has the #3, 4 oz. of wood for multiple racks of ribs is spot on ... it won't overpower your spares unless you're using mesquite. I typically use a 50/50 blend of apple and either pecan or hickory, though cherry is quite nice as well.
The Flavor Savor from Smokin-It is a great tool but if you've prepped your ribs overnight (held in the fridge) they'll contribute to the humid smoking environment so it isn't 100% necessary, though preferred. Spritzing with apple juice is even more flavorful but you'll need to add 20-30 minutes of smoking time for each time you open the door.
Divot's correct about time but I've had them "wander" from just under five hours to well over six. Fat content, how you butcher them, the environmental variables ... all contribute. My advice is that you take a peek at five hours and look for pull back on those bones. If it isn't there, come back in 45 minutes ... rinse, wash and repeat as necessary.