A number of Mod Ideas. Which do you want?

[llamaRCA]

They won't sound the same if I'm taking some random person and tacking lines on to lydia. That will break immersion and annoy, the exact opposite of what I want. Though Lydia has so few lines already that it wouldn't be hard to completely redo everything she says.

 

You clearly aren't understanding me because you don't have experience with this so I will explain further.

 

Often when the voice actors record for Beth they do more lines than just for the one part you are interested in expanding (they act for more than one part). This means you have other lines you can use to make more dialogue. I am not suggesting you use "some random person" for tacking on lines to Lydia. What I am suggesting you do is find out the voice type of the NPC whose voice you want to use (if it's Lydia then you would find that voice) and then you can go through all of the voice files of the actress who voiced Lydia. You can use something like Audacity to cut and paste those files to create new dialogue or if you find entire lines that suit your purpose you can use them as you find them. This is regularly done by modders, including me. I assure you if you are using the same actor's voice work and they are using the same accent/voice, etc they will sound the same. However, I'm not trying to sell you on doing it this way, I'm just telling you that it's a viable method for expanding the dialogue of a NPC.

[surasshu]

Ahh, curses, why did I even make that an option? Clearly more difficult than many of the other options. Especially if I really want it done well.

Haha, it's definitely the most ambitious. But I think it'd really make the biggest difference, too :D