Give Camsoft a call, they will tell you what all is needed.
You almost always keep the axis and spindle motors. The drives are a big question, Camsoft compatible drives use a 0-10 volt analog input signal. You really have to get the details here for a good judgment.
Not a big cost item but you need 5 volt differential quadrature encoders throughout. All of your I/O will be connected to Opto 22 terminal boards. These can run at any common control voltage.
Your major items are 1)good P.C., 2) Galil or camsoft motion card, 3)Nudaq I/O card, 4)several terminal connectin boards and PC cables, 5)Camsoft software. As mentioned above, a big variable is what drives.