Hi, As far as i am aware there are only 2 suppliers of the 'slabs'(foam filled) in the UK and these are imported from China. The companies here in the uk then add their own locks etc., then brand them as their own. I think the only different ones are Rockdoors which are stronger and also there are some composite doors made with a solid timber core. There are some new doors being made in Ireland which look impressive and seem much more stronger than the foam filled ones. I think there are a couple of suppliers in the uk, i have been looking into them and they are a bit more expensive than the common composite doors but overall seem much more secure and are double rebated so seal much better than the single framed ones. They can also be hand painted over in the future if required or fancy a change. They have videos of them on youtube and will give you an idea of the differences. Hope this helps.