reg:PMDC motors attached to Gear boxes
have chosen motor 2 by thinking it has high no load and full current rating so that it can produce high torque


High no-load current compared to full-load current indicates the motor is not very efficient. Efficiency an be estimated as (full-load current minus no-load current) / full-load current.

Motor output power is full load input current X voltage x efficiency. Torque (Newton-meters) = Output power (Watts) X 9549 / RPM

In determining the power to drive a mechanical load, you must not forget to consider the efficiency of the gear. A small, inexpensive speed reduction gear can be quite inefficient particularly if it is a worm gear. Half the motor torque could be lost in the gear.