First of all, thank you, IC2 Dev Team, for this awesome project that you maintain!
I have good exp in webdev (php,js) and desktop apps (delphi, c#), and recently I've started learning Java and went through some simple tuts about Minecraft modding step by step, had no problem with that.
But in some a bit more complicated things I've stucked. Need your kind help 
How can I extend ItemArmorQuantumSuite in my mod? I want to use this as a basement for some advanced type of Quantum Armor.
I've tried different things, but none of them helped:
- decompiling ic2 source and importing ic2.core.item.armor.ItemArmorQuantumSuite (this lead to many errors)
- looking for some clues in GraviSuite mod source (did not understand how author uses functionality of QuantumChestplate + adds a new one)
So my question is - how to create a new armor which will have all Quantum specs + some added by me?
P.S. Maybe someone could also advice me where I can learn advanced things like that?
Thank you!