Step 1: Basic stove top smoker
1.) A square , rectangle or round metal pan about 2 or 3 inches deep and big enough to hold the butt. A 10 by 12 inch pan is large enough that it can span 2 of the stove eyes. This is not a requirement, but is nice support, especially for larger butts.
2.) A shallow pan a little smaller than the main pan. This pan will sit over the wood chips and be a drip pan to catch the fat juices.
3.) A metal or wire grill rack to support the meat and raise it above the fat in the drip pan.
4.) A lid. This can be as simple as a sheet of aluminum foil crimped around the edges.
In a nutshell that is all you need for the smoker. You can find stove top smokers on the internet and in restaurant supply houses. I bought a medium size one on the internet several years ago for about $25 USD. (Pictures included below) The one I purchased has a lid that works fine for ribs and tenderloins. However, for butts and most briskets I have to use aluminum foil to create a lid because the main pan is not deep enough for the lid to clear the larger cuts of meat.
For the larger main pan you can find disposable aluminum pans in most grocery stores here in the States. The turkey roasting pans will work although they are larger than you actually need. In the same area as the roasting pans you can usually find smaller pans that can be used for the drip pan as well. Racks from small gills work good for supporting the meat. I have even used the metal shelves from toaster ovens.