Hard to judge. Sound like the maple will blend nicely with the counter. I would use the lightest color possible for the backsplash. The counter looks very dark and it is a matter of taste if you want to have both the backsplash and the counter dark.

I would go with a very light neutral tile so the BS doesn't compete with the countertop. You could go with a ceramic subway or travertine. I think you'd have to be careful with the travertine that it was "quiet" without too much color variation which would compete with the formica. Here's a link to a tile that might work.

Take your formica sample & your paint chips and head to your local tile store and just look around. I don't think it will be too hard to find a light neutral tile that will work.

I really like your formica and paint colors and I think they'll go great with your cabs (which sound beautiful). I look forward to seeing what you choose!

Here is a link that might be useful: corn silk tile