I'm hoping to find time to program a more extensive, polished app; but I'm hedging my bets by releasing this small portable program (no .NET runtimes; it can be run from a thumb-drive if desired):
KyrTTS is Kyrathaba's Text-To-Speech application. If you have Microsoft SAPI installed, this program can be used to convert English text (contained in a text file) into WAV audio.
Here is the download link for the non-UPX-compressed application in a zipped file (333 Kb download, 626 Kb extracted).
And
here is a download link for a UPX-compressed version of the program (281 Kb download, 286 Kb extracted).