No, gears are more difficult. The spacing between the axles must be exact. A toothed belt gives some more flexibility. Look,at how most 3D printers are built, although they must have linear motion, which is even more convenient for belt drive.
Two motors is really not going to be easier than one. Double the gears, double the mounting hassles, extra overall width, extra power consumption. I would go with direct-drive and one motor before considering two. Have you done your torque calculation yet?
Also, while it is possible to put two motors in series or parallel from one controller, it is better to have two controllers paralleled on the Arduino side. The modern controllers in the A4988 and DRV8825 are really smart and they do a lot of clever stuff to the motor. Look at the options available here: Pololu - Stepper Motor Drivers
Pololu probably also has lots of gears and other useful hardware in their robotics section.