Unless this has changed since I was last there, almost all rental cars are stick. Automatic has to be arranged beforehand

From recent experience renting a car in the UK, I can tell you that this has not changed. Automatics are still the norm. GPS units are available (and I found it mostly worthwhile) as many sites and addresses are available by postal code alone.

Also, I would add that speed cameras seem to be very common now all over England and Wales.

I think this is a great resource, I hope your brother has a wonderful trip.