Yes, you can use Text Speaker to get the audio files you want. Type your entire message once and convert it to an audio file.

Next, go to the ‘Edit’ menu, select the ‘Replace…’ option. Enter the name of the person for whom you have created the audio message earlier and replace it with the new person's name at all places.
After replacing, again convert the text to an audio file. Repeat the process, making sure you rename the audio files so you do not overwrite previous ones.