We are using Bird Australian Migration Agency they have a website
www.ozmigration.com.au.
They were recommended by friends and the agent, Cheryl, has migrated from the UK herself so she understands exactly how frustrating the process is and always keeps us up to date on whats happening. She always answers our e-mails quickly and calls when we need to talk to her (this is all included in their fee which for our 136 visa is AU$2,530) around £980. :D