I agree with Fatback Joe and Homebrew, do not over cook it...... I know from experiance.
Use a water pan filled with apple juice or water to help with moister in the smoker.
Wrap it in bacon if your not going to stuff it, the bacon will help keep it moist.
Try butterflying it and stuffing it with spinach, riccota cheese and roasted red peppers. then fold it up and tie it and cook it with a very light smoke (apple, or maple)
Or try stuffing it with cranberrys, chopped walnuts,Gruyere cheese.
either way you cook it I would take it to an internal temp of 150 to 155 and take it off the pit, Tent it in foil and allow it to rest for about 10 minutes It should reach an internal temp of 160 all by itself then.
Be sure to use a drip pan to catch any juices while it's cooking, and make a pan sauce with the drippings, white wine and juniper berrys ( if you don't have juniper berrys use some butter and a little honey).
Good Luck
Ron