The best crossover in a direct drive would be a 209/X9 or Prostar 205.
But since you need space for 8 adults and 5 kids you should look at an X30 ('06 or newer)
An attitude adjustment plate should help the slalom wake, but don't expect it to be great like a direct drive....still much better than any I/O though. You should be able to find one under $50K.
I was njskier on here.