I checked out a few PC based phone systems. The cost is still too high to be feasable for most potential customers. The main cost is in the telephony boards. I do know that you probably won't get the support, reliability, AND cost you want without going through a rigorous process to become a dealer. You can check out Artisoft Televantage, and Altigen Altiserve. I know that they have been in the market for a long time (comparitively speaking) and have gotten the processes down the best from my research. Hope this helps, keep me posted.