Need help with Mill/Drill retrofit

I am currently starting to do a cnc retrofit on a Mill/Drill. I have
most of the mechanical items (ballscrews, bearings, pulleys, belts,
etc.) and have started to replace the lead screws. My plan is to
keep this machine dual-purpose manual/cnc. I am at the point where I
need some help with the control side of things. I need some help in
locating "low cost" servo motors, controller and/or card for PC
interface. I will be using an old Pentium 133 for this retrofit so I
don't think I will have any problems with control capability. Even
though I am trying to keep the cost down I have opted to go with
servos because I have more experience with them. I have done some
searching on the web for PC motion cards and found that most are out
of my budget for this project.
I have visited Jeff Davis site and got some ideas form there, but as
for get this thing connected to a PC I will admit I need help. Any
thoughts would be appreciated. Remember I am trying to keep the cost
down.

Trevor