I prefer a propane unit. I have a GOSM 9 Great outdoor smokey Mountain large cabinet 16" deep, 24" wide 36" high. You need at least 16-20 inches from the top rack to the water pan if you intend to smoke hanging sausage. Most of your smoking will be at relatively low temps, sausage usually starts at 130F and ends around 170F pulled pork or briskets are done hotter at around 225 F. If you get a smaller version you may need to install a needle valve on your gas supply to get down to the lower temps.I use my own wood, i just split it down to kindling size. I would stay away from units that are electric as they just don't have enough heat to work in the winter, also stay away from units that use pre-formed wood pucks to make smoke. They can be very pricey. The charcoal/wood burners can be difficult to keep your temp constant. This is very important when doing sausage, if the temp gets above 175 in your smoker it will cook the fat out of your sausage and they will be mealey and dry