Thank you guys for your input, appreciate the help.
About the custom build, I am not too sure if i want to go that route. It's the same reasoning that vbironchef stated.
The client wants the build, based on the software requirement which they will be using the computers for.
There is no budget set as of now. I have to find research and give the price so, if you can help me find something similar to software requirements.
The requirements of the software is listed on this website http://www.avimark.net/gtka/hardware-requirements
Now the question is: Do I need a server to install the software on it and have the 2 workstation connect to it? or just 3 workstations will do it?