Can anyone suggest one for me.

The prices range from £48 to £140 on ebay.

Im lost, whats the difference - what about this one?

http://www.ebay.co.uk/itm/Honda-CBR400R ... 20bf8356bd

Depends on how you ride your bike. If your a road user go for something like the DID or Tsubaki X ring with steel sprockets, if you race some prefer renthal alloy sprockets to go with these chains. I personally dont think I would go for cheaper Iris chains, some seem to like them but reading around there seem to be a lot of negative feedback, although no doubt people use them sucessfully. The choice is yours.