the solution involves buying a 100 euro product with 6 customizable buttons (cool product but expensive). Anyone know of cheaper alternatives for a keyboard buttonset (between 4 and 20 keys)? Probably standalone numpad (with customizable keys) comes closest but maybe someone knows better.
Another project i've done was with a Rasberry pi. A benefit of that would be that the system is self contained. Their Python GPIO library is one of the easiest i've ever worked with and you could have it easily launch Chrome or Firefox programmatically and play audio without a monitor.