I could draw up a diagram, but it's absurdly simple. Just take a "T" off your hot and cold supply tubing for the second valve. In my case, I ran the rain head tubing from the supply valve up the shower wall, and up in the shower ceiling (attic floor) joist bay. There is a finished attic space above, though this part of the attic floor is behind a kneewall. For that horizontal run through the attic joist bay, the pipe is pitched for drainage, so when the rainhead valve is turned off the horizontal pipe does hot hold water. The bay is also insulated above the pipe. You could have exposed tubing within the shower if you wanted. If you want to have a traditional shower arm, you can do it. But these heads can be rather unwieldy at the end of a horizontal shower arm that extends out of the wall. You could always fashion a bracket to secure it to the shower ceiling too, that would prevent drooping. The reason I usually install rain heads from the ceiling is that I like them to be in the middle of the shower, not near a wall. You are correct that a true rainhead, you want it horizontal, not at an angle. Do understand there are no hard and fast rules as to how it's plumbed. I simply have my preferences. If you want the rainhead close to the wall, no worries! If you want to keep the plumbing out of the ceiling but still get the head towards the middle of your shower, I did a search for "rain shower head ceiling bracket" and got these three hits, they might give you an idea on how to make up your own solution:

Dragonflygirl girl, in my experience, water pressure in the water coming out of the pipe no longer has much influence on how ”hard” the water falls in a rainhead. My thinking is that the water ”uses up” some of the kinetic energy it gained from being under pressure in the pipe in the effort to spread out in the 12” diameter rain head. I don’t think having the water in the pipe until it is closer to your head matters much for pressure. In cold weather, though, I think that it does have a noticeable influence on the temperature of the water that hits your body. I might seriously consider a longer down pipe.

Thank you all so much! Seems like #1 is the clear winner. That's good, because it was the one I was leaning towards! I think it works perfectly with the urchin. Glad you all like the chandelier. Can't wait to share finished photos with you all. Justterrilynn, thanks for the suggestions -- #3 is the exact one we are using in our den, which will be about 20 feet away from the pendants. I think we are doing it in black though, like this (which will pick up on the black cord of the pendant): As for the others, I really love the delicate simplicity of #6, so we may use it as a pendant in my daughter's bathroom. And I think the Tom Dixon beat lights might show up elsewhere in the house too. I just visited the Tom Dixon showroom last weekend, and I was smitten: In other news, I just finished our lighting plan and turned it over to our contractor! So happy to have some decisions behind me. Many thanks to everyone for weighing in.

Thank you all for your input! I drew it on paper and the lights look too close together using the 1/3 rule (28" from edge), and they look too far apart centering them on the sides of the sink (13.5" from edge). So, I've decided to split the difference and center them 21" from the ends. This gives 24" between the pendants in the center of the island, and 12" from the edge of the island to the pendant. Even with hubby being 6'5", I don't think he'll hit his head. I drew it out (side view and top view below). Please let me know if there are any fatal flaws in this plan! p.s., our ceilings are 9', so I can easily have the bottom of the pendants 36" from the top of the island - thanks for the tip Jan!