I have made some progress in the idea of design for my Portable PS2.
I think to use 6,5" screen, the 7" look to big, and I don't like the 4:3.
And for the battery I am going for two 5000 mAh LiPo of 75x55x10 mm, thank you, @Gman, for helping me with this part !
Here is the idea :
And for now I...