I just installed multiple LED ceiling lights that are enclosed in metal canisters sunk into the ceiling. They are identical in size to the ones I replaced and are dimmable. Also replaced several track light spots with LED as well as all the incandescent bulbs in the house.
They were made by Utilitech, which is sold here in the US at Lowes. Not sure if that brand is available in the UK or not. but a lot of companies making them now.
Much lower wattage than the ones replaced and much brighter.
Edit: Expensive (about $325.00 for the whole house) , but they should last longer than I will.