[Asterisk-Users] Asterisk and VoDSL

[Sascha]

Hi, I'm new to telephony Software and Hardware, so please excuse my
questioning.

I plan to set up a little system, using Asterisk and VoDSL via Belcacom
or Scarlet here in belgium.
We are yust a little 2 man company and we are not always in our office.

My idea is, to get VoDSL and set up a system that works as following:

A customer sends SMS or phones to our office-numbers, if we are out,
Asterisk checks the CallerID or if hidden, sends back an sms or says,
that the customer should send or type in his client-number.
Then Asterisk send an sms to the one, who is working on that customer,
so that we can make call-backs if nesessary. 
Connecting Nagios to the same system, could also send sms, if something
on our servers goes wrong.
I also want the system to be able, that of course more than one caller
can be handled at the same time.

I know that Asterisk can handel this, but does "sms via fixed line" by
Adrian Kennard work, using VoDSL??
And what other hardware do I need (except for the server with digium
cards) to get this idea running??

As externals I'm planning to use 1 analog phone and maybe 2 headstets
for each of us if we are in office.

thx, Sascha