Most people will use wood in a situation like this. My best suggestion is to consider carpeting the staircase, You can build it up, then carpet right over it. Laminate just can't be bent to fit, and machining the edges to a long miter is near impossible for a DIY. The resulting edges would be razor sharp also.
Maybe you should check with the manufacturer to see if they have a product, a recommendation or if they even recommend using laminate on staircases. The way that laminate floors 'float', I don't think I'd want laminate on a staircase.
Anyway, good luck with this one.