Yes, stall detection is important with a two-motor setup. Modern digital stepper drivers will do this for you.
As Clive says, a typical single-motor setup will need a Nema 34, where my machine (gantry with spindle, etc, is probably around 40-50kg) is driven by two 3Nm Nema 23 motors with 2005 ballscrews. Not an optimum configuration, but it works ok up to about 5000mm/min.
