Like most people doing their first mill conversion on the cheap, I chose the SIEG X1 Micro Mill. I purchased mine from Minitech.
It uses 1mm pitch lead screws for all three axes, so conversion to CNC is relatively simple.
Automatin Direct supplies the Sure Step line of stepping motors in Australia. I bought the STP-MTR-23079, which is a NEMA-23 sized 1.17Nm (276oz-in) model.
My 3-axis bipolar driver is made by Xylotex, model XS-3525/8S-3. I'm using a 24V switchmode power supply, but may go to 30V or so if necessary.