I have just come across this company- Saorsa tours- https://saorsatours.scot/?fbclid=IwZXh0bgNhZW0CMTAAAR27iZNcfIKQQ0CS95HRuoa4WMKXlnCCd1g7ZBk2exvRpxpDHI9k9ZfR96w_aem_ATjjYqj0mL4S5f8-sEwKFTrA1O3zLKCkd11KK96U4O5rDUK05WnYrMvxv6sdSpC3IltJz222oo7AGNH0cTBS8mpE
who run private day group tours from Inverness. They can be bespoked.
I don't know anything about them. But they may be worth a look if you have a group. This is just trying to help people, who can then make their own decisions.
Yes I know they are not cheap. But compared to a Rabbies Tour maybe not hugely more either