THIS IS PROBALY A TERRIBLE IDEA, MAYBE??? (read on!!!)?

ok so i want to b in jazz band for 7th grade, and as of right now i play clarinet. I would like to play in jazz band, because i was hoping that my band teacher would let me play my original choice (trumpet:) because now that i think about it, it would b like starting band all over again, so instead he said i should probaly stick to saxaphone for jazz. so i was looking at someone else's question for Switching from clarinet to saxaphone and i found out that the tenor sax is in the same key as my clarinet, but the fingerings aren't the same (btw all saxes have the same fingerings). WHY IS THAT IMPORTANT?? BECAUSE I AM WORKING ON MY MAJOR SCALES FOR MIDSTATE BAND AUDITIONS IN THE WINTER!!!!so now12 more scales shouldnt b as hard!!!! yay! plus, i think it's less popular than clarinets(we have no tenors as of right now) just as i got excited, i sat and thought TENOR SAX????? last year whenever i tested for band i didnt have enough air to fill up an alto. THERE'S NO WAY I COULD FILL UP A TENOR I WOULD B BETTER OFF PLAYING SOUSAPHONE!!!!! im a 12 year old girl and im about 5foot1 and im confusedddd(: i guess my real question is... TENOR vs. ALTO?????