He's just looking for a good reliable ski boat and he says that everyone tells him not to waste his time with I/o and spend the extra cash and buy a direct drive, but no one has any valid points to why they don't like the i/o.
Unless all you are going to do is ski/wakeboard, you can shove that direct drive up your culo. Ride like crap, no room because the engine is in the middle of the hull, don't back up for chit, can't beach it....

If he is really serious about skiing tell him to try to score a V drive or a Z drive tournament style boat. Mo betta

As for the I/O's, they can't be beat. Models to pursue would be the Volvo SX with a 350 Chevy or either the Mercuiser Bravo I or the Alpha I..
If he's buck up and wants the ultimate, look for a Bravo III or a Volvo SX Duoprop.
You will want to stay in the late 1990's just for good parts availability.
GT