I did a Scotland trip at the end of May from Bath (round trip 1600 miles). 1st night in Peebles, 2nd night in Beuly near Inverness via Braemar and Tomintoul, 3rd night in Ullapool via Lairg, Tongue and Durness, 4th night in Fort William via Poolewe and Gairloch, 5th night in Helensburg via Oban and Lochgilphead (tried to go over the Pass of the Cattle but the sleet and rain convinced us to turn around just before the top which was really hard given the horizontal sleet and the gale force wind.
Best views definitely the Cairngorms up to Tomintoul. Most lonesome road the one lane A836 after the A838 turn off up to Tongue. Best two biking roads definitely the A816 between Oban and Lochgilphead, and the A814 from where it comes off the A83 towards Helensburgh. Both roads very bendy, and the A814 like a rollercoaster ride, and just a little bit scary at speed not really knowing where the road goes next over the hump and what might be coming the other way.
200 miles a day is about right as you get time to stop for tea and cake often. The 400 mile plod up and down the M5 is a pain but quite easy really.
