Regarding the TTS specifically, I remember looking into TorToiSeTTS back when this stuff was first coming out. You can generate ElevenLabs quality audio with it, but it's insanely slow. In fact, when I was looking into it, it seemed like ElevenLabs may have been using a (much faster at the time) version of TorToiSe TTS, given the output is so similar.
According to the linked Github page, they seem to have solved the speed issues now, so it might be worth looking into. Of course, the other commenters have provided solutions that are pre-integrated into the LLM, but if you're just looking for TTS this could be worth checking out. Also worth noting that this requires an NVIDIA GPU.