Hmm I think Ender Zoo adds some additional difficulty to the generally really easy pack (especially on the server you can lose no items in the overworld!?). Regarding Big Reactors vs. Mekanism, we have to check this for balance first. Applied Energistics has already been in the pack and will be updated to the latest version with the update.
Regarding Tinkers Constructs:
What is meant by old Tinkers Constructs? And what is the new Tinkers Constructs? We will update it to TConstruct-1.7.10-1.8.8.build991.jar which is the latest version which is available for Minecraft 1.7.10. The newer 2.x.x versions of this mod are only available for Minecraft versions 1.8.9+.