Hello and welcome.
If you think that VOIP is the way to go for the company you might want to post this enquiry over in the
VOIP forum.
You'll find many people here with opinions about what system is best (and it's usually the one they work on
), take the advice they give but check out what your support is like for each product from local vendors as without this you could find yourself asking an awful lot of questions here which your vendor would be able to answer.