Delta or Moen have decent quality and are at a lower price point. That's why the big box stores have a lot and sell a lot of them. Choose your system components from on-line catalogs or shop in the store, get the specific part number pieces you want, then shop on-line and compare prices.

Too many things invading the space. Skip the rain shower. Just put a handheld on an adjustable bar and call it good. No diverters needed. No excess expense. Or large amount of lost space. Simple is always best and cheapest.

I agree with live_wire_oak...that much plumbing in such a small shower would feel like climbing into the cockpit of a fighter plane.