Alomar is not going to come anywhere close to reattaining stud status again, that much is clear. That said, he should be able to hit around .280 with 15 homers, 70 RBI. With Piazza out, he has been moved from the leadoff to the #3 spot in the lineup, which should mean more production. Alomar should get around 15-20 steals.
Eric Young and Michael Young should both wind up with the same batting averages as Alomar, in the .270-.280 range. Eric has the advantage that he will steal more bases, and could steal 30-40 bases, if that's what you need. However, he has almost no power and will have very low RBI and homer totals. Michael will steal fewer bases than Alomar, but should put up similar power numbers. Since he is otherwise the same as Alomar, but with fewer likely steals, going for Micheal Young makes little or no sense.
If you need more stolen bases (probably around 15 extra SB over Alomar), you might want to consider replacing Alomar with E.Young. If you would need to maintain your power categories, I'd stick with Alomar, especially with him now batting in the heart of the lineup.