Dave, Hanuman said that about the 300mb of ram in his second post in this thread.

A texture file should sute the situation. Its all based on what your final rendering res will be. But the max res maya can handle with out starting to generait a lot of errors is 8192x8192.

There are 2.54 cm in one inch. so 180cm at 72dpi is 5098 pixels wide. Well with in maya's limets.