As it turns out, several sizes and options exist. Rather than just "buying our Smart Boards", we are now faced with various unexpected choices and possible hurdles to consider.
Size is a factor -- for Bansho to work successfully, we need as much space as possible, not only to display a potential "problem" for students to solve, but also to be able to "post" annotated solutions and students share them. We want to be able to keep solutions up as others are added, in a format that is big enough for all to see.
In addition to size, mountability needs to be considered. A wall-mount unit takes up considerably less real estate in the classroom, however, it is also less flexible, i.e. should we ever decide to move classrooms or schools, or rearrange our own classroom, the board is up where it is, and that is that!
Another monkey wrench is Board purchasing agreements. Apparently our IT dept and Smarttech have arranged certain pre-approved "packages" for purchase, which may or may not include the specific boards we are interested in!
Happily, we have already connected with our school's IT Resource Support Person, who has some insights into different boards, as he has seen them used in other schools. We look forward to his guidance as we make our purchases in the coming weeks!