Cheers!
By now I've found out that Philips is a big player in this market. They have some very nice products. The downside seems to be that all their products use the .dss (digital speech system) file format instead of eg. mp3. This means the use of proprietary software.

Fortunately, I've also found software called Express Scribe which seems to be free (and works with the infinity pedal!), so the use of this .css file format doesn't have to be that bad.

I'll continue looking, but I'm already a bit further.

Thanks for the info guys!