janisj, I'm certainly not comparing the distance that can be covered, just the tolerance for all of us being in a vehicle together. Aside from sheep and cattle on the road, I've certainly dealt with those other hazards of driving on two-lane roads, at least throughout the Appalachians. Definitely have to make sure the car's a manual!

Manual is the norm for UK car rental

"Definitely have to make sure the car's a manual!"
Get an automatic if you are not familiar with driving on the left side of the road - changing gears with the left hand is very awkward and it is just one more thing to deal with in a confusing situation.
I agree with the others that you shouldn't assume more than 30 mph when calculating travel times.

Driving in the Highlands with an automatic would be no fun at all....!

First of all driving a manual with left hand is not all that complicated. Highly recommend manual for gas consumption and for driving the ups and downs of the highlands.

Just some suggestions. In the Loch Ness area near Kinggussie is the Highland Wildlife Park. When I took my nephews to Scotland (10 and 14) we all enjoyed our day there. We took some time on our own and then went on one of the walkabouts with a ranger who was funny and informative. We saw wolves being fed as well as otters, wild boar. Many of the animals are being bred for reintroduction into the wild in Scotland.
There was a drive through section of grazing animals. (Low speed limit, another good reason for a manual car). Also a lovely cafe for lunch, as well as picnic tables for bring your own. We carried a box of non perishables--bread, peanut butter and jelly, fruit, juice boxes, cookies, paper towels, etc. in the trunk, but bought cold drinks and ice cream at the cafe.

We were there in the beginning of July and in Fort Augustus, there was a round of Highland games. There were animals of various breeds and events that children could participate in without prior registration. The boys loved this event and I found it interesting as well, so you might check to see if the games are on when you are in the area.

We also did the LochNess stuff and Urquart Castle in the Drumnadrochit area.

On the way south from Fort Augustus toward Stirling, we stopped at Speen Bridge for a few minutes to see the monument to British special forces. There was beyond that a place to visit, Fairyland I think it was called, where we walked through and saw boggarts, and all sorts of mythical creatures native to Scotland. It was a bit touristy, but the boys thought it was fun.

In Edinburgh we visited the Museum of childhood on the Royal Mile and just outside the city on the Dalkeith Road we visited a butterfly farm which was magical.

We liked the Isle of Mull better than Skye. We did some hiking there, visited two castles, picnicked near the sea, visited Staffa where we saw puffins up close, and hiked on Iona.

We had two weeks so could be more leisurely than you, but just thought to throw some ideas out to add to the itinarary. I know you'll have a grand time no matter what you choose!

Some thoughts. Try to avoid driving for the first 24 hours you are in the UK. You need one full night of sleep in a bed before trying to navigate on the wrong side of the road while suffering with jet lag. Believe me you need your wits about you.

Please understand driving is more stressful. Yes the motorways are like our interstates, but you can quicky get on one lane roads. We stuck to Edinburgh, Fife, Sterling and Glasgow (returning to Edinburgh) and were suprised the number of times that getting to a destination required us to thread a needle, squeezing a Land Rover through tiny one-way lanes. I swear I've seen golf course paths that were wider.

Once you get to the final leg of your journey, Edinburgh is best seen without a car. We were lucky to have accomodations that had a car park the first leg. On our return our host gave us neighborhood parking passes, but we had to circle the block more than once to find a place. Everytime we moved the car it was the same deal. It would have been easier to walk, take a bus or a taxi. We could have easily got all day bus passes for teh cost of parking.

If you return to Glasgow you can easily take a train to Glasgow and then an airport shuttle once in the city.

Irishface:
I agree that changing gears with a left hand isn't that complicated but it is one more "unnatural" maneuver in a confusing situation (I have rented a manual in England & Ireland and one of the cars didn't shift gears easily). The driver is on unfamiliar roads and has to change gears mainly at intersections and turns, where intense concentration is required if he is to look in the right direction and stay on the correct side of the road. The last thing he needs is problems changing gears that will may deflect his concentration away from the road (and don't forget the two screaming kids in the back seat - lol)

Thanks again. We'll have been in London for 5 days prior to taking the train to Scotland so we'll be time-zone acclimated. And I've driven in England before so I'm comfortable with the "wrong"-side gearbox.

irishface, I'll definitely check out those suggestions for the kids. I was already thinking that returning the car as soon as we hit Edinburgh makes sense.

I think you're in a good place with your itinerary at this point... one thing that we found neat was that there are some castles in which real people actually live (and are open for tours). We found a couple by accident and it was really neat to see working kitches, televisions, modern bathrooms, etc. worked into a castle.

We also found the Heritage Pass a big money saver... plus you didn't mind making a stop for just a few minutes since you didn't have to pay for admission. it also provides a great map that gets you to a lot of more abandoned castles, stone circles, etc.