I know what you mean about the lack of British armour, you don't see much of it. Unfortunatly, my primary focus when it comes to armour is WW2 German, so i don't know a lot about allied kits.
I know Takom are due to release a GRANT at some point. Given they have released modern British armour you don't often see, this could mean their may be others to come.
AFV Club has a selection of Churchill variants, the earliest being the Mk III. Italeri did several versions of the Crusader, but they are rather old.
I am a Norfolk man and i glory in being so
On the bench: Airfix 1/72nd Harrier GR.3/Fujimi 1/72nd Ju 87D-3