Suggestion for hardware (making answering machine)

i want to make an answering machine (a simple project for college)
i am planning to use trixbox to make it work.

so i need some advice on hardware? of course, it shouldn’t be expensive, around 400-500$. i figured TDM810B and 2 FXO (2 telephone lines), probably 3-4 FXS modules? is that hardware overkill?
thanks in advance

building this is trixbox is not a big challenge, you get better grades doing this only with asterisk.
overkill? don’t know how many lines you need to have incomming.