They all come in .png format and the dimensions are 1000 x 1000 but they can of course be resized.
The head used in the preview is by Creinie and TDA.
You can edit as much as you want! Go crazy! You can redistribute your edits freely without permission! You MUST credit IchiLewis for the original textures! It is recommended that you check the readme. * These are strictly for non-commercial use only.
Leaving a comment to say you have downloaded them would be appreciated but is not required. Thank you.