Looking to get vag com and appropriate cable to use with the following cars

2008 Audi A6 3.0 TDI
2003 VW Passat 1.9 TDI
2003 VW Beetle 2.0

What software and cable do I need? Have downloaded version 409-1 for free but have no cable. I've seen them on ebay for around £10 delivered but also seen this http://cgi.ebay.co.uk/VAG-HEX-CAN-US...item230a19d42a

What's my best options guys? Don't mind spending the extra if it's going to be more benificial