SATA or SATA2? G5 iMac

Hi guys,
I have decided my hard drive is dead and need to get another. Due to the urgency of things I can't wait for online delivery and need to get one off the shelf... this is the model of my (pre-intel) iMac http://www.everymac.com/systems/apple/imac/stats/imac_g5_1.8_20.html

and this is the drive I can get locally and quickly http://www.pcworld.co.uk/martprd/st...null&sm=null&tm=null&sku=039891&category_oid= but I have conflicting info on the G5 iMac supporting SATA2... and I'm no hardware expert.

Any advice would be great thanks!

That drive will work, incidentally, there is no such thing as SATA II
http://www.serialata.org/namingguidelines.asp
There is a ton of info there!