I would second RonGinger's suggestion. I put 3 phase motors on both my lathe and mill with variable speed controllers. The soft start alone is a joy to use.
You might want to try Electric Motor Wholesale www.electricmotorwholesale.com. Check out the line of Leeson Metric motors. I recently retrofitted my mill with a 3HP unit in an IEC-90 frame. Electric Motor Wholesale had the motor in stock and delivered quickly.
