I agree with Neal. Which guitar would motivate you to play and practice more? There are also physical size considerations. Some people have difficulty with full sized steel string acoustics (and even electric solid bodies) -- especially as beginners.

There are 3/4 sized acoustics available. Another option is to clamp a capo at the 2nd or 3rd fret of a full sized guitar. This makes the neck shorter and the strings easier to push down on. When you get more experience built into your "guitar playing muscles" you can stop using the capo.

Good guitar playing to you!