Hellow; Nice! Obviously everyone has their own ideas about this but here some of mine personal findings: Park4Night: very useful indeed and from time to time a small campsite (shower time).
We do not bring our bikes (and never did this when we visited Scotland) but this is of course possible. Instead: we walked there a lot.
We took the ferry from Zeebrugge to Hull, but this line is no longer available and I think we would use Calais or Dunkirk for now.
We always go during the Easter holidays and have not seen any midges yet. However, I am sure that you can also make a memorable, nice trip during the summer months in Scotland. I don't find it busy there, not even during the Easter holidays, on the contrary: you will often feel alone and remote and this is actually a wonderful feeling. Of course there are busy places; I have read a lot that the NC500 has become a busy route and is even a bit of a victim of its own success; Even before the route was named that, we drove it (kinda) and it must be said: it is a beautiful route, indeed.
On the way to or back from Scotland, possibly visit the following: Lake District and Lake Windermere (beautiful boat trip) and afterwards the Windermere ferry to Hill Top, Sawrey (Hawkshead): home of Beatrix Potter (Peter Rabbit).
Tan Hill Inn (Yorkshire Dales): Britain's highest inn (got unbelievably drunk there), overnight right opposite the Inn and delicious breakfast; Warner Bros. studio tour (Harry Potter) at Watford; Windsor Castle (and sleep at the coach parking): always our stop on the way to Camper Jam. Canterbury (stayed overnight for a few times on the coach parking and nice walk into town); the white cliffs of Dover (nice walk).
So, the Isle of Sky: very nice but there is indeed more to see than that: so without obligations just random where we were already, it's rather eclectic and from different journeys:
Here we go: Angel of the North at Gateshead followed by Hadian's wall (including Housesteads Roman Fort); Scotland with Neptunes Staircase, Fort William, Ben Nevis, Commando Memorial at Spean Bridge, The Jacobite Viaduct at Glenfinnan, Portree (we always eat fish & chips there/ what else did we get to know during our trips in the UK: marmite, haggis, marmalade, scones, sponge cake); Old Man of Storr, Applecross (and the road to it: Bealach na Ba), Balmoral (you can overnight in the parking lot), Urquhart Castle (+ Loch Ness and the exhibition center to learn all about Nessie), Dunnet Head, Wallace Memorial and much more (we will come back) and especially enjoy the surroundings;
What more: Edinbrugh with the Greyfiars Kirkyard where there is much to see ... and not to see ... (ghosts), Linlithgow Palace, birthplace of Mary, Queen of Scots; Blackness Castle; railway bridge over the Forth, Falkirk Wheel and the Kelpies; RRS Discovery and 'the Law' a war memorial in Dundee; St. Andrew's Abbey.
And more: Loch Lomond; Oban: ferry to Barra (very beautiful there), Vatersay and South Uist and North Uist; Skye, Kilt Rock; Dunvegan Castle; Kinloch Forest; Eilean Donan Castle; Leanachan forest at Spean Bridge; peninsula Kintyre to the Mull of Kintyre; There is more, but find out for yourself, it will be great!
Greetings
Calibusje
@Barra
Maybe for an other trip: Wales. Conwy, Snowdonia, Pen Y Pass, Mount Snowdon; Beddgelerd with Llywelyn's dog; Penmaenpool Toll Bridge; Portmeirion (‘special’ beautiful and where 'The Prisoner' was recorded here; The series also inspired Iron Maiden to the song The Prisoner, on the breakthrough album The number of the beast.); Aberystwyth.