Don't know what "The Last of Us" is, but at least I can help you with the cuatro question (just converted my bari into a cuatro xD)
Cuatros are Latin American instruments descended from the Renaissance Guitar and are much older than the ukulele, but are similar to the ukulele in that both have *re-entrant tuning*. We all know ukes have "high G's" or "high 4ths", but cuatros do the opposite where they have low 1sts - the 1st string is lowered by an octave. Cordoba has the cuatro to pay respects to the cuatros in South America, but really, other than a tap plate and different strings, a cuatro is usually not that much different from a baritone ukulele. It's funky to pick sometimes (your melody string just dropped an octave.. takes getting used to), but the depth of the tuning is a nice change for those who are searching.
More info from Dirk (Southcoast Strings) here:
(Tips on Cuatro Tuning):
http://www.southcoastukes.com/007.htm
(Introduction and Cuatro String Sets):
http://www.southcoastukes.com/cuatro.htm
Regardless, Cordoba makes good ukuleles, so the cuatro is a nice introduction into the cuatro form and style, and if you don't wanna dabble in cuatro, it can make an interesting bari uke! xD