We're remodeling our bathroom and will be installing 2 separate shower heads - one fixed rainhead and one handheld. We'd like the option of having just the rain, just the handheld or both at the same time. I know we can get two separate valves and trim kits, but is there a single control unit that could do this? One valve, one trim and a diverter? If so, please direct me to a specific brand and model, as I can't tell from the descriptions given online. Thanks!