When I do any kind of outdoor bbq, I like to use a charcoal smoker. I like the flavor that charcoal and wood put into the meat and there is no other way of duplicating that flavor other than using the real thing. Right now I use two different types of bbq smokers.
The first type, which I use most often, is a barrel type charcoal smoker with an offset firebox.
One of the main reasons I like this charcoal smoker is that you can use it as a bbq smoker or a bbq grill. It has plenty of room to fit large cuts of meat such as beef brisket or a slab of ribs. Using the charcoal smoker is easy. If you are smoking a cut of meat, build your fire in the fire box on the end and place your cut of meat in the middle of the grill area. You will have to set the vents on the end and on the top to try and maintain a constant temperature (usually 225-250 degrees for slow smoked meat). Basically, you want to create a "draw" that pulls the heat and smoke from the fire across the meat and out the top vent. If you would like to use it as a bbq grill, just build your fire like in a normal grill in the main barrel.
The second bbq smoker that I use occasionally is an upright barrel type charcoal smoker.
I have found that this bbq smoker works great for cooking chicken or smaller cuts of meat such as roast. It can be rather difficult to cook larger cuts of meat such as brisket or ribs. Also, the meat sits directly over the fire, which I don't like to do when I am slow cooking meat. Chicken and smaller cuts of beef can cook a little faster.
Homemade BBQ Smoker
I have also had the pleasure of cooking on a homemade bbq smoker that worked with excellent results.
There are many types ofcharcoal smokers out there and many ways to make or use them. If you are shopping for one, make sure that it will give you enough room for the cuts of meat that you like to cook.
Other BBQ Smokers
There are also a large variety of gas and electric smokers on the market today. Many people enjoy using these and have used them with excellent results. Again, my preference for a charcoal smoker is simply because of flavor.