We had a way solid bath fitted several years back as a 'shower bath'.
AFAIR it is an Armitage Shanks Armorcast (or similar) but I can't seem to Google this or an Armitage Shanks home page :-(.
This bath is wider and longer than standard, is much squarer in the floor area, and built like the proverbial brick walled outhouse.
It is not so good for soaking in the bath (squarish profile doesn't encourage lounging) and takes a hell of a lot of water to fill it.
However as a deep sided shower tray it is superb :-)
Having said this, we did our second bathroom in a standard acrylic bath from HomeBase (rejected the pressed steel because the profile gives a very narrow floor area) and this works fine - just not quite so much area for the feet. It seemed alarmingly flimsy before fitting (see previous displays of angst on this NG) but once it was in place with the brackets screwed to the wall and all the legs adjusted it seems fine - nice and stable.
We located the original bath at a specialist bath centre in Colchester - (Falcon Plumbing and Heating Supplies Ltd - 01206 767366) they seemed to have an amazing range of standard and non-standard baths - so I think you should be looking around (Yellow Pages etc.) for specialist suppliers instead of major chains like HomeBase, B&Q, Plumb Centre.
HTH
Dave R
BTW is it just me or is Google now almost totally unuseable?
Every search is covered with 'search sites' and no details of the site you really want.
Any other search engine better?