Expanding on what @roarah says, I would use a temp and volume control at each fixture if two people are going to use it at the same time due to preference in temps. In my one control shower with a valve that can switch from rain shower, water fall, and hand held spray, the temp does need controlling, as the hand shower is closer to the body and the water doesn't lose as much heat, as does the rain shower, as it travels through the air losing heat before it touches the skin. The rain shower head will be a nice head to use near the door, if you need to place one there. The regular shower heads would need more shielding with glass, from getting onto the floor. I have a 3' wide shower that is 5' long, with the glass on the long side. My doors both open in and out, at about 29" wide each. The 5' long wall is measured in the rough-in stage. It actually is 58" once tiled. My rain shower head is at one end and my hand held is next to it on the wall in a porter (small holder). It is not a problem reaching in to turn the fixture on. I primarily use my rain shower, and if I need a blast of water to rinse my hair, I use the waterfall feature. I hardly ever use the hand held except to rinse the shower floor. BTW I wipe the entire shower down with a large microfiber towel following each daily shower. I never have to clean my shower :) Its been in for 3.5 years and I only clean the pan every 3-4 months with a spray cleaner. My shower is spotless, no discolored caulking or grout. I have a stool that is portable in my shower. I would have had to put the built in at one end if I wanted to go that route. I like having the movable stool, I can move it under the rain head and just sit there relaxing, when I feel sore, sick, or just tired. I don't have a tub in the room, so this is the next best thing. I bought an inexpensive gray topped stool with aluminum adjustable legs, and I love it. It matches my gray shower pan. It is rather clinical with a modern look. It is light weight and easy to move. I thought about getting a teak stool, but couldn't settle on one that wasn't too expensive. I think my room is nice looking with my shower, fixtures, and shower seat. I have a lighted exhaust fan in the shower too. Have you looked at pics on Houzz showing what you want to do?

Agree with what Mizlizzie wrote. I try to keep the bottom of the rainhead a minimum of 7' above the tiled floor. You can mix drop arms. Most are universal 1/2" thread. Generic finishes like Chrome are pretty much universal, you can mix and match from most any manufacturer. If you have a designer-type finish then sure, it makes sense to stay with within one manufacturer's product line.

You may want to consider the average shower curtain length to help with this decision.

Thanks for feedback- we have a tub in the guest bath on current main level. For the pop-up we can put a tub in the kids shared bath. They are getting to an age where they probably like standup shower like our current 3x5 but can do combo for family bath on resale if that is better for families to bathe younger kiddos down the road. I think it is a 50/50 mix in our area (NoVA/DC metro). The really small remodeled homes don't have them. The ones we may 'compete' against would be new builds which are larger square footage. So if no tub (which we are fine with) is to find a design for a really nice shower but feel airy and spacious in the room. If we go no tub, should we reduce space and widen walk in closet or do something with laundry closet? Or just make shower a little bigger - if shower at entrance would that be a wall or just go with frosted glass? Our master bath had entrance adjusted so DH could get his 'sitting space' and place a TV or something on a wall there (also to avoid door to door direct line Feng shui with opposite bedroom. Current laundry is in basement so we thought we should at least have a mini w/d upstairs. We are blowing out some walls on main level so don't want to lose storage space on main to place laundry there as a compromise option that had come up.