To gather the raw data on the schools the State has an OK site:
Interactive Illinois Report Card
Your agent should be able to help with more about specific attendance areas.
As to the "safety" of a house that is 15-20 years old that would not be concern for most homes from the 80-90s. Code enforcement is pretty good in those towns and nothing funky should come up. Of course you ought to make any offer contingent upon a thorough and professional home inspection. Your agent should have referrals.
If you mean "safe" in terms of "they will hold their value" that is another can of worms, and personally I feel that the odds of losing money if you plan to live in the place for 5-7 years are quite low, much has to do with being sure you thoroughly investigate the right price to pay for the home, again something that your agent ought to be focused on.
Good Luck!