I personally don't think they stack up to the official suzuki ones. Considered putting them on mine, but quickly decided against it
There are a couple cheaper alternatives but I don't think they're worth considering. That one is the cheapest I'd consider. For example -
http://www.twinshack.co.uk/prods/306.html
If you're feeling especially adventurous you could consider the 'SVXR' package?
http://www.twinshack.co.uk/prods/528.html