Yeah that Kechele you have is way too big for you. What's your skill level, airs can be done on almost anything really, the sprocket you have is basically the ...lost Rocket I believe, and although your board is big for you in the sense that at your weight you don't need that much foam, its not a bad board for doing "airs". It has a wide nose for help landing that reverse on a somewhat stable platform and if the rockers are like the Rocket its got plenty of tail rocker right at the fins to help get that pop out of the lip you need. Get airs on your current board, then go to an epoxy dumpster diver or something Dane rides cause his boards are for airs - <----- that is heavy sarcasm man do not take the last part as advice
If you were to get another Sprocket (since you know this board and it's a good reference point for anything you might be looking at), I would go down to a 5'8" x 19.5"-19.75" x 2.33" or whatever dims the Sprocket has in the 5'8" range--that probably will give you close to the right volume. Plus the shorter you go the = less swing weight = easier to spin and lift.
Good info on this thread if you plan to go the SUP route too.