I bought the ultimate ear ones from last year's UK HU meeting, the guy had a setup inside the bar.
I think they were about £160, and I got a set with earphones, a 'blank' set, and the moulds for my money. I find that as they are a complete seal in the ear, and are made from shiney plastic, that the inside of my ears begin to get hot and itch after a couple of hours use, and I have to stop, take them out and say "Ahhhh, that's better"
But they do work extremely well, reducing the outside sound level by 75% or so, but you can still hear your engine and everyone shouting 'Dozy Ba***rd' as you cut them up. the earphone set come with a 3.5mm stereo socket.