For the text to speech with Tomtom you need specific maps that support cspeech and then use a computer voice that supports text to speech (Susan and Simon I think they are).
Only chart I can find regarding what models support TTS out the box is for USA + Canada maps. I'd like to think most of them have the default support but to avoid having to fiddle around with different versions of maps. Each release of map usually comes with 9 different flavors depending on the Navcore version + features. For example only 7056, 7057 and 7082 support cspeech. But you won't know what version of map is installed when ordering a device. Nor do I know if you can pick what map via TomTom's Home app. As I've only got a stupidly old TomTom One (V2) with a whole 500mb of internal memory, and I've not looked at what my Tomtom rider has but both are pretty old now.