You can control duration and timing for each individual frame, there are many transition effects to choose from (including fade in fade out) and you can synchronize with an mp3 or wav file for background music. Once you're happy with your slideshow, you can create a standalone .exe file which will play the slideshow.
Best of all this is a non-crippled trial, which means you can use all the features for 30 days. If it is a one-off need, that basically means it's free.