Cheapest "panoramic" option is of course to shoot on a regular camera and crop the image. This works in principle with any format, a 4x5" camera gives a usefully-sized image (even with a 3:1 panorama, the image is still 4x12 cm). A few (or a lot of) $$$ more will not necessarily give any better quality, just a handier or more portable package (X-Pan, Noblex, etc.). No known pitfalls, you will probably find that you like either 2:1 or 3:1 format better (I like 2:1, I find 3:1 too long and thin). What format to buy? Probably the bigger the better.