I’ve heard good things about the Wigwam / Cabins at Loch Tay.
From there. I would go along to Aberfeldy and walk round the Birks (nice walk for the kids) Up the A9 to Aviemore – you could take in the Highland Wildlife park.
Carry on up to Inverness (you could either go to Fort George or on a Dolphin watching trip).
From Inverness head down the A82 to Drumnadrochit and either go to Urquhart Castle or the Nessie museum. If you have time you can go into Glen Affric too for a walk.
From Drumnadrochit take the A86 to Kyle of Lochalsh and over the Bridge to Skye.
Once on Skye you could spend as long as you like. Highlight for me would be a drive around the Trotternish Penninsula form Portree to Uig taking in the sights as you go. From Uig Down to Dunvegan – visit the castle and take the seal tour.
Once you are finished with Skye take the road down to Armadale and the ferry to Mallaig.
Mallaig to Fortwilliam taking in the Nevis range. The down the A82 through Glencoe.
That should take you a few days and covers some of the nicest scenery in the UK