i have hit the 3 c above the staff, but it was not controlled. The highest note I can control and hit consistantly is (get this) the 2nd d above the staff.
About the jazz clarinet stuff. If its not a high school band or your not totally unbeleivably amazing/playing solo, you do not have much of a chance. In most jazz bands, the sax players double (or triple) as clarinet and flute players.