You can only have 1 WAIT() at a time.
But you can do it manually ... nothing "Tricky".

If the variables for each preamble are the same you could ...
Code:
Wait4Preamble:
    debugin [preamble]
    IF (preamble != %10001000) AND (preamble != %01001000 ) THEN Wait4Preamble
    debugin [mydata2, mydata3]
Or, if the variables are different ...
Code:
Wait4Preamble:
    debugin [preamble]
    IF preamble = %10001000 THEN
        debugin [mydata0, mydata1] 
    ELSE
        IF preamble = %01001000 THEN
            debugin [mydata2, mydata3] 
        ELSE
            GOTO Wait4Preamble
        ENDIF
    ENDIF