It would make more sense to use the same one the iPhone does
And put a little circle of magnets on the bottom left AND bottom right of the back of the display! Then you'd be able to power it from either side, and fix one of the biggest annoyances with all models of laptop I've always had - that you usually seem to have your plug on the opposite side of where the power connects. You'd think that would only happen 50% of the time, but it is some sort of quantum mechanical thing similar to having to flip a USB-A connector three times to plug it in.