So does this actually make a 3rd .esp file to check in the Data Files? I need to get those in the right order so they don't over-ride modded textures.
It does, but like the previous texture packs you may not have to use the ESP. Instead add the BSA to the Skyrim.ini file like this:
[Archive]
sResourceArchiveList=Skyrim - Misc.bsa, Skyrim - Shaders.bsa, Skyrim - Textures.bsa, HighResTexturePack01.bsa, HighResTexturePack02.bsa, HighResTexturePack03.bsa, Skyrim - Interface.bsa, Skyrim - Animations.bsa, Skyrim - Meshes.bsa, Skyrim - Sounds.bsa
sResourceArchiveList2=Skyrim - Voices.bsa, Skyrim - Voicesixtra.bsa
Backup the ESP file outside the DATA folder. This will ensure that any mods will be loaded after the texture pack.