Help with gearing needed, Ultegra Di2.

I want to get lower gearing on my stock Ultegra FC-6800, which is 50-36 X 11-32. I also want to retain the sweet Shimano shifting, so I'd prefer to stick with Ultegra parts.

Ideally, something like a 46-34 X 10-34 (don't know if even exists) would be the range I'd be looking for. Any...