Welcome to the obsession.
In your area you should not have any trouble coming accross a Bandera. Acadmey and Home Depot should both be reliable sources.
There are several members of this board that own Banderas, myself being one. There is a group on Yahoo dedicated to the Bandera. There is quite a bit of information available from that board, relating to modifications and other info pertaining to using the Bandera.
On modifications, I reccomend the expanded metal grate for the fire box, the baffle for the smoking chamber, and sealing the fire box and chamber, all of which are discribed in detail on the Yahoo board. I would also reccomend adding a spring and washer to the smoking chamber outlet flap, so that it will allow more consistent adjustment of the flap. I used a spring from a "Weed Wacker" and a couple of fender washers in addition the the press on axle nut that you get with the unit. This keeps the flap flat against the chiminey in all locations.
Weber "Q", Weber Performer, Weber 22.5" Bar-B-Kettle