I'd keep everything together UNLESS the main shower head is very far away from the entrance to the shower. You don't want to get wet until the shower is up to temperature. Even so, a better solution would be to have a clear sliding glass shower door vs. a glass swing door so you can keep the plumbing on the same wall.

Transitional Updates - Naperville, IL · More Info

Your question says you want to put the "shower head and arm on opposite walls", but do you really mean you want to put the controls on the opposite wall as the shower head and arm?

We have the shower head, rail and hand shower on one end, and the controls on the other end. The shower is 48" long, so you can reach in one end and turn on the control, and when the shower gets warm you can step in, and then into the water stream. We built it that way on purpose, but it would have worked either way.

The shower in the picture in the last post is a good example of why the "same wall" solution might not be convenient. Due to the placement of the toilet you would enter the shower on the left, and then have to walk in and turn on the water while standing under the shower head. This can be a cold experience if it takes a while to get warm water.

Bruce

Unless it is a 2-person shower, I would put them on the same wall. This bi-fold door by Aqua-fold both folds and pivots in and out of the shower stall. That should make it easier to reach in and turn on the controls with it pivoted to the outside of the stall, and then you can unfold it to close while the water temps adjust. I think with a larger shower you could could actually install two of these to meet in the middle since they make right and left versions.

@Bruce in Northern Virginia: "Due to the placement of the toilet you would enter the shower on the left, and then have to walk in and turn on the water while standing under the shower head. This can be a cold experience if it takes a while to get warm water."

Notice that there's a tub spout even though there's no tub. They probably let the water run from the spout until it gets warm.