is it possible to add some kind of ethernet module to an arduino uno or another?
also for my arduino i need one with 9 digital inputs and 3 digital outputs.
anyway thanks for the help 
Like the Ethernet shield?
Insure it has a w5100 ethernet IC. That is the one supported by the ethernet library.
The ENC28J60 requires a different library and forum support is limited.
you can use the arduino ethernet , in my opinion It is better than arduino uno + shield ethernet