Gold/jewelry guidance

I have been wanting to get a chain that would look good sitting on top of my shirt. I want it to be a cool accessory without looking like too much. I checked out a few in-person - see example pic. I’m curious if others have thoughts or guidance on ideal lengths/weights and stores. I am based in nyc. I have also considered whether to go higher carat gold for quality/longevity or get something plated that I can beat and does less wallet damage. Appreciate any thoughts!