Thank you very much !
The screen module costs 13$ on eBay (search "1.8 LCD module"), and the screen alone costs 7$. The library is this one : http://www.bestelecs.com/download/lcd/1.8SPI.zip.
I don't know if I will do an instructable, there is a lot of information in the video, and doing instructable take a lot of time, and I'm not sure people are interested in that...
Here is another project I made with this screen module : r0d0t's stuff
Edit : I did some modifications to the library.