More extruder heads will allow you to use different colours or different types of material at the same time. A second extruder is also required to build PVA/PLA support structures around items as they are printed.
Polylactic acid (PLA) is popular in 3D printing as it cools and sets quickly. Unlike ABS plastic, it is biodegradable and therefore better for the environment. It can be used to build support structures for other printouts, as it can then be dissolved leaving no marks.
Cubify CubeX Trio
76% have it
12. maximum creation size
This is the biggest size of object that you can print.