running eq maps and another custom UI

[Castonu]

This sounds like such a noob question but just not understand I guess. I use EQ maps and would also like to run another custom UI, whether pieces or a full one, in addition to the map. But everytime I DL another custom UI I cannot get both to work. Am I installing the custom UI into the wrong folder?
If so what folder should the additional UI be unzipped to?..Any help would be appreciated. Thanks..