Hello matsk,
Just be aware that Optus block both web sever port and mailing ports ... so you won't be able to use your SME box to run your own mail server ... you will have to use there e-mail still ... you can get arround the port 80 block for web server.
I used to be with Optus but left for that reason. And that there just to expensive compared to ADSL these days.
You should be able to setup your connection using the static IP feature as Optus cable is a static IP.
Only if they still use the login and password feature still.
Regards,
Tib.