"The device has rs-232 serial port communication "
USB to RS232 adapter
"and 4 programmable I/O lines digital or analog."
incomingByte = digitalRead();
incomingInt = analogRead();
"Moreover I need to save the information of the device into an internal flash memory www.adafruit.com, SD card shield"
Adafruit Data logging shield for Arduino [v1.0] : ID 243 : Adafruit Industries, Unique & fun DIY electronics and kits
"that I need to get later using an USB port "
built into Uno
"and a ethernet port."
ethernet shield
http://arduino.cc/en/Main/ArduinoEthernetShield