FStyleFormat poperty for leading/line spacing?

Is there such a property that would allow me to specify the leading or linespacing in a listbox? Lineheight? Let me know, I didn’t find such in the help notes.
Also, what is the best way to load from an external file (txt) into a listbox? I can do it in a dynamic textfield but cannot figure out how to do it in a component. Thanks!
Best,
nate