Firs of welcome in our comunity. You even filled your sys specs
As for your question I'll give you a straight answear: it's hard, very hard.
I have build a couple of desktops myself, but when I opened (not build) my first laptop I was amased. All the pieces are so tightly crowded that I think they must have designed even the sata ribbons to fit.
The main things you would need for a laptop would be:
- a frame, iron/Al frame on which to place all of the other components. On the bottom part of the frame the mobo should be placed. This frame should be of rectangular shape, as the cmponents that sit above the mobo must be fixed
- after you managed to build a frame and bought all the parts you need (mobo, CPU, ets) you can place them on the frame and start thinking at the cooling system. It has to cool the CPU and also to create somekind of an air current in the case that cools the other cmponents (NB, SB). You have to be creative on this one... I suppose the OTES systems can be a good inspiration
- a lot of luck
Just my 2 pennys