I have found this website to have everything I have needed: http://wires.co.uk/ I started off with getting one of their variety packs.
There are loads of bead suppliers out there. The one that I use (partly because I am used to the layout and can follow it) is: Jilly beads
I have found that steel or metal hooks are the best and easiest to use with wire.
Please note: These shops and websites I have listed are simply the ones that I have used and have been happy with. There are many more out there and as such this is only meant as a guide.