I have a similar situation with a mini split. Aesthetically, I think vaulted would be the way to go, it just requires a couple of extra considerations. I did drywall and insulation in the ceiling the ceiling to help with climate control, but made sure to install some blocks where I knew I needed to hang certain components. For the mounts you'll need something designed for vaulted ceilings in order to get everything level. I used these: https://www.firefold.com/products/cav1 . They accept a standard 1.5" NPT drop arm, I ended up just buying the appropriate length NPT nipple at a hardware store.
