If your goal is to attain a sleek, polished look then you need not look any further. Go short, simple and fly or long, flowing, and bossy.
If a full look is what you're looking for, we suggest 3-4 bundles and sometimes more, depending on the lengths you choose. A good rule of thumb is the shorter the hair the fuller it will look. The longer the hair (lengths 20 and up) the more you should purchase.
The hair can be colored, bleached, and styled per your desire.