Do people use these, and if so are there any particular brands that people recommend?
Bloody oath
Brand and type will depend on harness you use. I use seat and a NP high hook. Plenty of options. 
Sent you a PM.
Mineral
You are required to wear them for racing.
On the bay freesailing, some do, some don't. I wear one.
You have to be careful if you wear a waist harness that the pfd (umm thats personal flotation device) doesn't get in the way of the hook. The kayak ones sit nice and high. I prefer the thin impact vest type. Some have a big zippered pocket back and front that you can put a bit of foam in for additional float or a sheet of lead for ballast. Mine is neoprene and even with nothing in it it provides bit of float and a bit of impact protection. Mine is an old style Airrush kiting vest. I saw the same thing with a "Liberty" badge on it in a magazine once. I doubt that you can get one of those anymore. Board Crazy has some similar vests but I suspect they only work with seat harnesses - not sure though.
Hags, yep thats it.
The reason I went with that one, is some times the vest will ride up and the loop strap fits through the seat harness hook, keeping it all together. (I had a used vest generic brand prior, that my Son used wake boarding)
Plenty of arm movement, and an added is Winter, its keeps the cold out of chest area
Probably others about, but I liked this one and recommend it. Helps in the "over the handlebars as well, something I think you know all too much about
Hows it going anyway, how long before you can come back out to play?
Thanks Mineral, the Pryde will be top of my list.
Yes I have got my Halo off, and no brace at all now 
but wont be sailing for a while yet, I'm scheduled for physio late Jan, I'll post more then as there was a bit of interest about physio 
Keep the laughs comin guys, this forum is a god send
