Help with Text To Speech please please (I'm getting a bit frustrated now LOL)

I did make a sub but I want to make some using text to speech. Why? Because although I have my own room, I am paranoid about people in my household overhearing me record the affirmations and that would be embarrassing. I went to the park to record the affs for the other one. Luckily I had privacy. So I wanted to use the robotic voices instead. But I can't seem to find a text to speech program that will let me (a) Have a big character count - free and (b) they seem to save as .mp3 but I want .wav or .flacc.

Any suggestions?

I'll ask amino too.

BTW I'm in the UK so suggestions that aren't just avail in the USA (though I think a lot of programs and sites are international now.

I DO want free versions (so please let me know)

Secondly, failing that, any paid versions and how much?