Harry,
Having just fitted a new chain to my Ten and breaking the chain tool I bought from M&P a few years ago (are they making chains stronger these days?) I was searching for a better and more robust product. After a bit of research I've just bought one of these from Ebay:
http://cgi.ebay.co.uk/ws/eBayISAPI.d...=STRK:MEWNX:IT
I believe it's a clone of the DID RM500 and there's an encouraging review here:
http://vfrworld.com/forums/mechanics...ool-km500.html
There's also a useful link to an article with photos on how to change your chain on the above link.
It's itching to be tried out (I'll have a play with it at some point on the old chain I've just taken off) and you're more than welcome to borrow it.
Simon