It doesn’t take long to install a mini-split condenser with a single air handler. Precast pad for the condensing unit, set the condensing unit on the pad (or buy a wall mount if you need to mount it off the ground), run sealtite to the condenser from the disconnect switch and pull in wire, drill two holes for the line sets and one hole for the power/signal cable that runs from the condenser to the air handler, mount the air handler, connect the line sets, plug in the power/signal cable, install and wire the thermostat. Seal the holes with silicone and turn the mini-split on.
It’s less than a day of work, finding a mechanical contractor to install equipment you furnish for $160-175/hr shouldn’t be hard, contractors just like ripping off homeowners because they don’t know any better.
You don’t really even need a mechanical contractor with precharged line sets, just ensure the disconnect switch is off and locked out before touching any line voltage wiring, and make sure you mount anything heavy to studs and not plywood or drywall.