Currently we are using Aficio MP C3502 and Aficio MP C2551 models.
These are on the Education Departments list of approved devices and all the W.A Govenments GEM list.
Ricoh has released a free app called Ricoh Print&Scan which enables android devices to print to these Ricoh printers.
The app has even the function for job accounting which works well with our current printing system.