Hi Steve, and welcome to the family!
I have a heavily modified gourmet, so I can relate to what you want to achieve.
First, the temp gauge is good for nothing more than a baseline reference after getting reasonably accurate cooking grate temps. You need a a fairly good reading, either with a digital probe (cheapo from hardware/dept stores will work fine), or, a long stem fryer thermometer inserted through a hole in the side of the barrel between the grates. Do a boil-test with the therm to verify it's boiling water reading (212* @ sea-level and approx. 0.9* less for every 500 feet above sea-level. A great reference chart can be found HERE.
If your temp reading is off, you can either just reference the correction or in some cases calibrate the thermometer to read correctly.
Second, time required for cooking is dependent on a barage of variables, so internal temp measurement is the best route to go, however, for a bone in shoulder/butt, a bone tug will tell you when it's ready to wrap/rest before pulling. Typically, for the tougher cuts of meats such as the shoulder and brisket, ~180* will give a tender slice and ~200* will be fall-apart tender. Oh, and don't stab the thermometer into a whole-muscle meat until after the first several hours...this helps you fall under the whole muscle meat guidelines for internal times/temps regarding the "danger zone".
Also, in the gourmet, the grate directly above the water pan is for steaming, not smoking, so whatever you put on it will actually get very little smoke. Temps between the two grates can vary significantly, with the area outside thewater pan running much hotter than insideof that water pan diameter, and the upper grate running hotter than the lower in the center of the grates.
Here's the main concern I have: the gourmet is a factory modified version of the smoke n grill, with the main improvements being made in the lower end. The charcoal pan is still not up to the task on longer smokes. Ash will build up and smother the fire. Also, there are a few ways to control temperature, being, amount of burning charcoal in the fire pan and amount of water in the water pan. More coals = hotter, less = cooler, more water = cooler, less = hotter. The addition of cold water mass is a temporary fix for too hot of smoke chamber temps. Evaporating water helps to keep the chamber temps cooler and adds humidity to aid in keeping foods moist.
If this is your first smoke in the gourmet, and especially your first smoke ever, you have chosen what I would consider to be one of the easiest cuts and one of the hardest cuts, butt and brisket, respectively....just so you know. I have smoked several butts and briskets in my gourmet, but I can only imagine what the frustration may be like without modifications. The ash build-up can be your worst night-mare, and if you need to add to the fire, you also need to remove the barrel from the fire pan to avoid air-born ashes from getting onto your meat. I always add preheated/burning coals to avoid the heavy coal smoke.
You may want to check out the food safety forums, if you haven't already...paying close attention to the low & slow discussion found way back towards the first threads (bottom of the last page). Also, drop us a line in roll call, if you don't mind.
Edited by forluvofsmoke - 8/20/11 at 1:05pm