Want a Wall Mounted Ductless Heat Pump

I advise against that.

Finding a Diamond dealer that will install it will be almost impossible.

Finding a qualified contractor that will install it will also be almost impossible.

Warranty WILL be a problem!

Either get a cheap unit and find a contractor who will just do the job (zero warranty) or pick a good contractor and have them supply the unit (full warranty).

The first approach is cheap but you are running unprotected. The second approach will probably be 2x or more the price.

Do not expect to buy a unit and have a contractor install it and expect a warranty. If the contractor is appropriately licensed, you might be able to pull off the warranty, but you will be on the hook to interface with the vendor, and you might be in the position of the vendor supplying the parts while you have to pay for the labor. When a contractor provides you with soup to nuts service, they mark things up to cover the cost of providing the warranty, but then they are holding the entire bag for the warranty service.

For what its worth, studied online, got my EPA 508 certificate, bought 5 'new-old-stock' Fujitsu units, and installed them in 2023. Zero warranty, zero problems. Used for air conditioning and shoulder season heating.

I think that's what they meant but it's worded a little confusing.

I don't think they meant buy equipment themselves and then have someone install.