There are currently very limited smiley sets available in SMF. If you'd like to see one added, please, open up a new thread in the SMF general support area with the following information:
#1: Download URL (pak included, as this will be converted for phpbb forums)
#2: Preview URL
#3: name of pack
Once you receive information that your smiley pack has been uploaded (I will reply to your post stating this), then you can follow the following instructions to enable it in your forum
#1: Login to your forum administration area
#2: Navigate to Smileys and Message Icons
#3: Click on Smiley Sets
#4: Click on 'New Smiley Set'
If a smiley set is available for you to use (sometimes there will be no smilies making the set unavailable) and has not been installed, you will be able to install this set. Add a name, and check 'default' (if you so desire).
If you requested a custom set be added, you will be given the set name in your thread.
Click on 'Save Changes'
Boom, you should have some new smilies!