[Asterisk-Users] Asterisk, Voicetronix, and Australia

[intent]

I'm looking to use Asterisk to replace my current PBX system. I'm in
Australia so I need to use Austel approved equipment. My plan is roughly
as follows:

- Get a box with a suitable card and install Asterisk
- Connect our existing PSTN lines to the Asterisk box
- Get suitable softphones/ip phones to connect to the Asterisk system
- Route all intra-office calls over our VPN
- Route all other calls out to the PSTN
- Route all incoming calls from PSTN as required

I have four lines and it seems like the Voicetronix OpenLine4 card
(http://www.voicetronix.com.au) is suitable for a setup like this. I'm
after war stories and any hints and tips from anyone who's setup a similar
system in Australia. What hardware do you use and/or recommend? What are
the pitfalls and gotchas that you've come across implementing an Asterisk
system? Are there any Australian case studies you can link me to?

Thanks in advance!