I have a smallish area (5-6 sq metres) adjacent to my house that I'd
like to make into an acid bed. We live in a very hard water area and
so it'll be vital to use rain and not tap water for watering. But I
also like the idea of low-maintenance and largely automatic watering
sounds attractive.

Since this bed is against the house wall and also adjacent to a
downpipe, I had the idea of positioning a water butt against the wall
and with a short head above the bed level to be topped up
automatically from the downpipe via a valve arrangement. (A refinement
might be to run some leaky pipes from the butt outlet down into the
soil of the acid bed to maintain a slow steady irrigation.)

What's holding me up at present is finding a water butt of suitable
proportions. I'd like it to fit snugly against a plinth wall (to be
supported on a shelf) and hence one face needs to be flat. It would
also fit the dimensions of the available space much better if it was
horizontal in proportion rather than than upright (in computer
terminology landscape rather than portrait format). In terms of rough
size something around 3 feet long and 15-18" squarish cross section
would fit well. It's also going to be a relatively conspicuous item,
despite being against the wall, so I'd prefer something that could be
fitted and finished as neatly as possible.

I can't find anything in my local garden centres that remotely fits
the bill, so my question is whether there are any specialist suppliers
of water butts (idealy with a decent website) that might be able to
supply one.

Thanks for any help
John Dann