Kim - It sounds like he isn't ready to give up wakeboarding to completely wakesurf, so I would suggest getting an 2000-2005 V-Drive malibu, centurion, supra, or Calabria. I have surfed behind all of them and they all are great wakes when weighted properly.
I would guess even a Nauti would work nicely, although I haven't surfed behind one. Nice wakeboarding wake though. Top of the line boats, just don't have any experience with surfing behind them.
I have a 2002 Cal-Air Pro-V and after a couple of days of playing with the wake, we got a pretty good big long wakesurfing wake. And it was easy to switch around the weight for wakeboarding (just moved one 600lb fat sac to the other side and away we went for wakeboarding).