The 18.5 is a wing keel boat for those who do not know this boat.
When adding a larger jib or genoa for use in light airs, placement of the jib sheet turning blocks is a consideration to include any winches and cleats. It has been over 20 years since I sold the last one as a dealer so my memory is fadding on that. Help please but I do recall putting one on. If you go that route, you may want to consider roller furling and I suggest the CDI or Flexible furler by CDI and I think the system would be an FF1 if not mistaken.
Contact the store site on this site and they should be able to help you out.