Just found these at £248 + pads
http://youraccount.ekmpowershop9.com/ekmps/shops/gtstuning/wilwood-powerlite-kit-for-sierra-uprights-42-p.asp
Do yourself a favour and do a search on gts tuning customer service on here, think you'll be looking elsewhere then.
If you do go for them, don't go for the smart pads as they arn't very good, mintex do a set of pads which are loads better with initial bite
i would get them from ben_copeland on this site, thats where i bought mine, very helpful
heres a link
http://www.locostbuilders.co.uk/forum/36/viewthread.php?tid=147178
thanks mike