mandolino
the easy way to do it is this way...1200 pounds of payload is about 6 pax with bags (and that is if they are slender pax)
so, look at 8 to 10 seat planes as your pax will probably be a little fatter and its better in this case to look at a bigger plane
now, I won't tell you what kind of plane to get...but a seneca or cherokee six/saratoga will probably be too small, so go bigger.