Selling old boat. Need new one.

Okay ive been wake boarding for since 2003 behind a johnson 80 outboard. Since then ive purchased a 2001 18" Trophy with a 125 outboard. Well now we are ready to sell the Trophy. I want to take wake boarding more seriously and get back into riding several times a week. My budget is 20k. I would love to just go out and buy a used wakeboard boat but I don't think that is the right choice. i live on the coast with no lakes. We have brackish rivers and then the ocean. I spend most of my days on the river but do go slightly off shore to go island hoping. Am I stuck with a i/o? If so does anyone have any suggestions for an I.O that puts out a good wake?