*SOLVED* CO2 gas cylinder - what fittings do I need?

[man_beach]

I used to use Midget Widget cylinders, then when they became unavailable I got a regulator and adapter for Sodastream cylinders - but they're not really up to the job as far as I'm concerned. I'm on my third Sodastream cylinder this year, whereas the Widget ones used to last me about a year!
It looks like I'm going to need to get a larger gas cylinder, if I can find someone who delivers.
As I said, I've got a good dual stage regulator, so what else do I need apart from a CO2 cylinder? I seem to remember from my college days and oxy-acetylene welding that gas bottles had some sort of spanner to let the gas out? Do you need to supply your own washers between the cylinder & regulator? Anything else? And if anyone can suggest a homebrew gas supplier in or around East Devon, that'd be a help as well!

Edit - got myself a spanner from ebay