There are several ways to adjust the length of a sleeve.  To make a long sleeve tropics-friendly, you will probably want to make a 3/4 length that can be further rolled up.  Taking about 4" off the bottom should get it to 3/4 length.  To adapt it for a turn-up cuff, straighten the sides of the sleeve from the elbow to the hem and add about 4" of fabric to the bottom of the sleeve lining that will be exposed when rolled up.  More next time...