2 pounds of sausage filled with 2-3 cups of whatever you like, kept at ~225* should take 1.5 - 2 hours.
Now, having said that, it is cold and breezy outside (in much of the US), so consider the fact that 225* may be difficult to maintain in your rig (not sure what you are using or where you are). If you are able to maintain 225* the times noted above are a good ballpark estimate, but as with all things, you should cook whatever amount of time it takes to get to proper temp. In this case, 165* to be safe.
As for wood... I like pecan... but I sure wouldn't turn down apple, cherry or most other fruit woods.
*Edit: I see that Fireitup was quick on the draw while I was typing. He makes another good point... let it rest for a while before you slice it. I normally wrap mine in foil and let it sit on a rack or oven mit, covered with a cloth, sometimes for a half hour or more. They will stay pretty warm for quite some time.