Customizable sprite character using multiple layers?

Full tutorial needed

I've been stuck on t$$anonymous$$s for quite some time, and I've never been able to find a full start-to-finish tutorial of exactly what I need - only bits and pieces as I searched, and half of them not even doing what I want.

What I want: -Unity to load and layer the individual sprite sheets (body, eyes, hair, clothes, etc.) together so that they appear in their correct locations. -To create a character customization menu that will automatically load resources such as hair into clickable options (so that I can add more options later without having to significantly rework code). -To be able to use t$$anonymous$$s same system to create randomly-generated NPCs to populate the world. -For t$$anonymous$$s system to be compact enough so that mobile platforms, such as iOS and Android, to be able to access all of (or at least most of) the character customization without $$anonymous$$ndering performance.

What I DO NOT want: -To have to combine all the posibilities by hand and import them into Unity as individual spritesheets (that's WELL over a million possible combinations, and would seriously $$anonymous$$nder or even halt performance levels) -To have to switch to 3D models. (I'm using Unity 3D because there are some 3D elements to the game, such as the map, but I already have nearly 50 spritesheets with 8-way directional movement and complex interactions, so I'll be DAMNED before I switch to 3D characters... Plus I t$$anonymous$$nk they look stupid in my case.)

I'll warn you, I'm very new to coding using Unity, and pretty new to C# as well. In essence, I'm a noob, so don't assume I know anyt$$anonymous$$ng. (I have a VERY vague idea on how to create animations, and I'm at least aware of a resources.load function. I already have WASD movement and have set up the camera to track the player character - I'm still trying to figure out how to incorporate click-to-move function and make it so they don't stack.)

These are the types of sprites I'm dealing with, so I'm a little worried that Unity will have trouble placing them in the correct positions. The bottom two are unmodified originals, but the rest have been made transparent. I can get the originals back if need be. http://imgur.com/gallery/llRpy

If anyone can w$$anonymous$$p up or find an in-depth tutorial for me, I'd greatly appreciate it. Like I said, I'm a complete amateur, so I need all the help I can get.

(Also I tried posting t$$anonymous$$s in the Help Room before, but it got stuck on "T$$anonymous$$s post is currently awaiting moderation," even though I thought Help Room questions could skip that??? Very confused as to why it's gotten stuck.)