Aussie, the ones i used were 20 mmx 3 mm in size, round ones like a 20 cent peice in size, they are 3,000 gauss in strength.
The place i got them was at, http://magnet-eze.com.au/ , if you go to that site and just a few lines down from " FAST - MAGNETS " you will see " click here " in red, do that, and then double click on " rare earth magnets ", then double click on " discs and rods, run down the page until you see item number
Red203, - $4.00 each, thats the ones.

If you do decide to get any , be carefull when handling them , they are very strong and if put them to close to each other [ opposite poles attract to each other ] they will slam together and if your fingers are in the way it hurts
Its important to put a small piece of Moleskin on the skin before sticking the magnet on, [ a tip from Mrs D]

As far as magnets that are in necklaces and bracelets, i can only say that years ago i brought one, that was suppose to help my neck, it was totally useless and i chucked it in the bin.

I used Elastoplast to stick them on with [ great stuff ] i know its available at Safeway, but probably Coles may have it too.
If you have any trouble obtaining any moleskin which i did,, PM me.

good luck
Brian