Hullo, Alan!

My son and I did almost the same trip in '96. By far the most convenient method of travel is to rent (hire) a car. That way you're at your own pleasure for scheduling. (Although the idea of leaving it parked locally for a day trip out on a bus or train also has much merit.)

While the UK trains and service are far superior to the US, they still run on their schedule, not yours. You can buy tix and make reservations in advance from the US via the Internet. Service is frequent in some areas, bi-hourly in others and perhaps once or twice a day to remote locations.

Bus service in the cities is great. There is also some inter-city service but I'm not detail familiar with it.

Some automotive thoughts from our more recent trip in July of last year...

--Cars and roads in UK are smaller than here in the US. Hire the smallest car that will accommodate your group and luggage. By bad planning, we recently had a full-size Buick type car in Scotland...on the B roads and smaller, it was like trying to drive a bowling ball through a drain pipe.

-- Do your research for rental companies and arrangements; prices vary significantly. Book way early--January is not too early for a summer trip. Get everything in writing (e-mail) and take printed copies with you, in case of SNAFUs.
If you're departing from an airport different from your arrival, make sure you can drop the car at that location.

-- Even if you prefer to drive a stick, rent an automatic trans. It's one less thing to worry about. See below.

-- As you know, they drive on the other side of the road and everything's functionally backwards, i.e., left turns are now easy and right turns are across traffic. It's not as easy as it sounds.
You're also sitting on the other side of the car from what you're used to, so simple stuff like looking in the inside mirror is also backwards. There is a mental shift involved and you WILL need to pay attention at all times. Driving there requires your full-time attention simply because you're not used to doing it that way.
The only time I really breathed a bit easier was on the dual-lane motorways (think Interstates or similar) where it was more 'point and shoot'.
On the two-lane roads repeat this mantra constantly: Keep Left, Look Right.
Start practicing it now. It will save your bacon.

Can you do this? Of course! My point: there is a learning curve. Be prepared.

-- All those jokes about sheep and cattle in the roadway? Believe 'em. (I have pictures...) We just missed gaining a woolly hood ornament on the last trip.

-- Things we never thought of: UK'ers also walk on the left, as on sidewalks, etc. Quite disorienting on a crowded street like the Royal Mile or in the Castle. (S'cuse me, pardon me, sorry--oh, wait, I get it...)

-- There are many good road maps of Scotland available. Get some, study and plan prior to the trip, and perhaps even write out daytrip directions in advance if your "second seater" isn't comfortable with navigation.

-- When you're planning each day, allow plenty of extra travel time to deal with all the wonderful things you'll discover. Pull off to take a picture of a loch, or stop in a village for lunch, or walk around a castle ruin. Go back to that museum in town. We have twice overplanned our trips and regret that; we saw a lot but missed a lot more. Serendipity awaits on every road.

I'll be happy to provide any other help I can.

Plan well and have a great trip! It's a beautiful land.

Peace
JT