Girlie,
It depends on how comfortable you are with big bags. I have a smaller frame than you, I admit feeling overwhelmed by its size. Stam & Venetia are about 15-16" across, my limit is about 13" now (i.e Blake/Elise are more suitable). Bags look even bigger in light colors. =)
Since your Black/Putty Stams are from SS06, they are both calf leather with suede lining? Which color will go with your outfits? Go with the color you like more rather than one that's hard to find and/or loved by everyone else. =)