how to include 3rd party code in plugin

Hi. Maybe my question is an offtopic, but it’s important.
I’m trying to create wp-plugin, which use Facebook Php SDK. So, plugin directory consisting a facebook php sdk files from github.
Question is what type of license should I use for this plugin, if I plan to realyze free (for uploading on www.remarpro.com) and premium (for selling) versions?

thanks, guys.