Travel to the British isles.

Hello, I am thinking of traveling to the British isles. MY last trip to London I planned alone. This time I am looking to book a company that does group tours. I prefer to go north to Scotland. The one time I did England I did a "Best Of" with a well known travel company. I want the trip to be less than 10 days and inclusive, in that hotels and some meals and ground transportation is all included. I am retired so I am flexible on time of year but I would prefer off season, Spring would be best. I want a good miss of country and city. Does anyone have any travel companies they prefer? I am not sure if this post will be allowed but I wrote more this time so maybe.