It's been a long time for me as well (more like 15 years), yet I recall a wonderful shopping area right in town. We didn't do a tour as we had a 3-year old with us, so we just walked around.
If you haven't already, take a look at Cruise Reviews' Curacao Page
for ideas for things to do. If you scroll to the bottom, there are reviews of a few excursions. Granted, some are old, yet at least they'll give you a better idea.
Are there specific tours that interest you? Perhaps those who have been to the places the tours stop can help further.