Some third-party designers have just one setting for Kiss. For example, a 10"x10" album size.
Since you can order any Kiss album, in any size, from the same design without needing to resize your spreads, you will only need to worry about one set of specs.
As long as your spreads are being exported and saved at 6,000x3,000 300dpi with a sRGB color profile, you'll be good to go!