Here's a Komoot map of the route: https://www.komoot.com/tour/407657180
I had a night at Glen Rosa, 2 at Seal Shore, 2 at Lochranza and 1 at Carry Farm (Caravan site on the map). Distance per day varied quite a bit (2 days 20-30km, 2 days 50-60km, 1 day 100km) - some people might stay at different campsites to make things a bit more even but it's a route that worked really well for me. Would have loved to have an extra night to come back to Glasgow through Bute - maybe that can be part of my next tour!
Ken Laidlaw sportive run by Hawick Cycling Club - good crowds, always good riders and a fair old crack in the rugby club house afterwards. Bloody hard ride mind, with lots of hills throughout. Good feeling when you finish. Looks like it has been cancelled for this year... dunno why but I haven't entered many as I have been racing. https://www.strava.com/segments/2167823 http://www.kenlaidlawsportive.co.uk/
Definitely hit the Trossachs around Loch Lomond and Loch Katrine. We don't have much in the way of mountainous routes, but what we have are rolling to steep runs all over the place.
If you can get yourself to Edinburgh or the Borders, have a run around a route like this: Check out my 140.9 km Ride on Strava: https://www.strava.com/activities/598107795
I did that yesterday, South from Edinburgh to Selkirk and back via Innerleithen. It's right by Peebles too, and if you're there you'll want to get yourself on a MTB and hit the red run there.
Have a great time!
The 3 Pistes challenge sportive route is up in the Cairngorms and goes from Pitlochry to Aviemore. Cracking route (very hard) but if you're up for a challenge, 102 miles and 8000+ft of climbing (165km, 2500m climbing) would be a good one.
You could always try something like Komoot or Cycle.Travel to decide on and discover routes. I used them for determining my trip last summer around the West Coast (unfortunately not on the Outer Hebrideas... maybe this year I'll go there), they helped me to discover routes which were previously unknown.
So yeah try those websites. maybe they'll show you a path which you hadn't seen before! :)