I can probably run 5hp without a problem in my shop. So, probably around 17 amps at 220V. I have one of those R2E3 mills that has the odd motor configuration where the spindle motor is between the Varispeed belt compartment and the solid ram. I took measurements the other day and it would basically need a short, fat motor to replace what's already in there. I thought it would actually be cheaper to make a motor relocation bracket and a idler shaft to put a more common Baldor Super-E motor in it's place.
I checked the voltage and amperage figures off of the data plate of my mill spindle motor, and it's really not 2hp but more like 1.6hp. So, by the time the power gets to the end mill, I imagine I have something like 1.4hp at the tool and perhaps 1.2hp useable without bogging down the motor to the point where it wants to stall.
Here is my mill. I hear it's a fairly common machine, but I have not really seen any of them around my town. Everyone else just had the regular J head Bridgeport's.
I do plan to run a VFD, so I would need a inverter friendly motor for it. That way I can ditch the Varispeed so I can run a little higher RPM's for the small tools.