Matt there's a old thread on here where they have a zip file with probably every frequency known to man. Go there and unzip it and you should be good to go for next year.
You should also consider visiting the area near the airshow PRIOR to showday (i.e. during practice/prep operations), it's good to have advance information on what they will be using. This is especially true for military UHF freqs, the UHF airband is HUGE and band searching for UHF MilAir takes a bit of time.