What are the Best Used Wakeboard Boats (15-20k)?

I've been wakeboarding behind a 1986 ski nautique with 500 lbs. of lead under the back seat. I get a great wake, but my wife is tired of slalom skiing through big waves, so we are looking for a good boat with an automatic ballast that will work for both wakeboarding and slalom...emptying lead bricks each time is not an option! I'd love to get a few suggestions of a good used boat that may work in the 15-20k range.
Thanks!