I have created a fairly simple mod that will do much customization for you and you can just move the mod from install to install. This will install your Portraits, Scripts, Characters and Player Soundsets (with strings). It does require the user to edit a few paths, but hopefully the instructions in the ReadMe are simple enough to understand. Let me know and I can edit it.
There seems to be some confusion as to the location of the override folder. Just to clarify where to create the 'override' folder if you do not have it already. Create it in your main Program Files install INSIDE the 00766 folder. Such as this: \Programs\Beamdog\Baldur's Gate Enhanced Edition\Data\00766\override