I have WiFly shield from Sparkfun. Is it useful for this?
You'd need 4 of them - one for each Arduino. But, that could work.
I have not expiriance vith visualisation. Is there a way to make a visualization on Excel, maybe with VBS.
Because the data is stored in Excel spreadsheets.
VBA (Visual Basic Automation) has capabilities to interact with a variety of Microsoft products, including Excel. It can also draw forms, with buttons, blinking lights, text fields, etc.