That's a beautiful boat David. Congrats. Where you spend your money on upgrades depends on how you plan to use the boat. Are you looking for general on the water fun or a dedicated wakeboard boat?
Regardless of use, if the prop is the original OJ Legend 3-blade, a swap to a new CNC 4-blade wheel from ACME or OJ would be first on my list. Props have come a long way in 20 years, and keeping the old one as a spare can be a day-saver.
1992 Supra Mariah - Red
PCM 351HO 285hp - PCM 1.23:1 Transmission
OJ XMP 4 Blade CNC 13x15.5RH
"People do weird things to boats" -Unknown