There are many shower sets available on Amazon, all metal construction, that are much more attractive and feature-rich than Delta or Moen shower sets that cost several times more! The only problem is they come with no-name mixing and diverter valves. Why wouldn't these companies make their trim compatible with Delta Multichoice valve? Are there any other brands (besides Brizo) that the trim works with the Delta Multichoice valve, or Moen valves?

I'm looking to replace the trim in my shower/bath - shower head, spout, and valve handle. The house came with a Delta Monitor set installed. I'm not interested in replacing the actual valve, and I'm wondering if I can just slip a new handle on in place of the old one? Is any Delta brand handle going to be compatible? Any from the Delta "Monitor" series? What about other brands? Is there any kind of compatibility guide for valve handles, or is it maybe the case that handles and valves have standards the way shower heads have a standard 1/2"? Thanks for any insight you can offer!