If you’ve only got a week then maybe look at doing the NE 250 which is basically an Edinburgh to Inverness loop. We’ve done that a couple of times. There are good aires at Arbroath and Findhorn and Kingsbarns amongst others.@SPR75 what did you decide in the end? I'm also hoping to do a jaunt to Scotland this year, but would only have a week. Journey start would be Darlington for us.
You can have a stop at Fortrose bay and go watch the dolphins at Chanonry point, which can be quite spectacular.
Or alternatively go and do a loop of Dumfries and Galloway and the Mull of Galloway. We did that at the end of last year after spending a few days with friends at their place in Gatehouse of Fleet. Some beautiful places up there.

Sunset over the Morne Mountains from the Mull of Galloway lighthouse.
You can stay overnight there too.