webmaster73
As I can understand, you can do it in this way:
1 - Install one 4images as usually, with local images.
2 - Install second copy of 4images on different domain elsewhere, in usual way, just like the first..
- Use your second 4images gallery with remote pictures, which are located on the first hosting. (I think you know how to use in your gallery remote images)
3 - Install third copy of 4 images elsewhere(and use config.php file from the second installation), or just copy all your files from the second copy to your third 4images. And it will run as a mirror of the second.
4 - if you want, you can make in that way (just repeat step 3) as many 4iamges galleries, as you wish, but be sure your first copy of 4images hosted on speed hosting (for from there your mages and pictures will directly linked to your other copies/mirrors), and, secondly, be sure that database of your second copy of 4images runs on speed and good mysqlbase hosting, for your all other mirrors will use this one database (they will not have no other databases).