Now my suggestion for the custom armor:
-kt requires paper as mentioned above
-to upgrade it you need to craft a special block which requires an anvil, an echanting table, a crafting table and 6 iron, the table would have 9 slots, an area to rename it and an area to add enchants to it, enchants cannot be added by a normal anvil
-it's upgrades are tiered and require the previous tier to be present:
•tier 1: combine it with coal armor and you get the same effects as it and it's protection, requires 5 levels
•tier 2: redstone armor, you get the effects it gives, but without the protection it's protection, requires 10 levels
•tier 3: obsidian armor, it gives you resistance and iron level protection, requires 15 levels
•tier 4: lava armor, this one is different, it requires two obsidian armor piece and 6 lava buckets(the bucket is consumed), requires 20 levels
•tier 5: the guardin armor, it gives regen, requires 25 levels
•tier 6: super star armor, requires the super star armor and 30 levels.
•tier 7: elytra upgrade, you cannot get flight using this armor, but you can get the gliding abilties of the elytra, requires 30 levels.
•special tier 1: allows you to combine the helmet with goggles of revealing to get it's effect, requires 5 levels
•special tier 1 upgrade: by combining the helmet with an additional thaumometer and sanity checker + some void metal to allow you to see the local aura levels and how much warp you have, can be toggled on and off with a keybinding, requires 5 levels
What do you think?
Well, ArmorPlus wont add any special blocks. it just adds armors and some items and recipes - but It will use normal Anvil Instead
•tier 1: combine it with coal armor and you get the same effects as it and it's protection, requires 5 levels - I agree
•tier 2: redstone armor, you get the effects it gives, but without the protection it's protection, requires 10 levels - I agree
•tier 3: obsidian armor, it gives you resistance and iron level protection, requires 15 levels - Well Diamond Level Will fit better
•tier 4: lava armor, this one is different, it requires two obsidian armor piece and 6 lava buckets(the bucket is consumed), requires 20 levels (What Exactly you mean) ?
•tier 5: the guardin armor, it gives regen, requires 25 levels - regen or water breathing ?

•tier 6: super star armor, requires the super star armor and 30 levels. - Well what ? here you mean regen ?
•tier 7: elytra upgrade, you cannot get flight using this armor, but you can get the gliding abilties of the elytra, requires 30 levels. - I have tried to do so but I didn't manage to do this (Elytra Armors BB)
•special tier 1: allows you to combine the helmet with goggles of revealing to get it's effect, requires 5 levels - Nice Idea
•special tier 1 upgrade: by combining the helmet with an additional thaumometer and sanity checker + some void metal to allow you to see the local aura levels and how much warp you have, can be toggled on and off with a keybinding, requires 5 levels - hmmm I will think about this
This are my answers ^^