remastersys in theory should let you create an initial installer ISO with the necessary bits. I'd probably use backup mode (which restores an identical system).
However, you can't actually install from it without a GUI (I usually install a lightweight DM (usually metacity) to the VM, run remastersys, then remove the DM after running the install). Its a rather hacky solution.
I'd really take Michael Hamton's advice about doing it the right way, and Adrian's advice of letting someone who understands the process well to do it. You don't want to end up with a hacked together, half broken system with too much wierdness.
Its worth doing once, well, and right.