I agree with David, and Manton, and Foo that it is better if the groomsmen do not wear the exact same cut of suit by the same maker.
David, I missed that your suit will be three piece. Excellent choice. If you really wanted to shine, you could do a contrast collar shirt with white pencil stripes on a light blue ground. Google "Prince Charles Parker Bowles wedding" for ideas. But the solid white shirt will look great.