It depends on what your goal is with your glasses. Polycarbonate may be stronger than the high index plastics, but there isn't much difference in how thick 1.60 is from the polycarbonate. The 1.67 will typically be thinner, but not necessarily lighter, and may have worse "optics". Some people are more sensitive to the difference in the optics, but the 1.67 will likely be thinner for you. I've read that the "aspheric" lenses have less of the magnifying effects, but I don't know much about ordering them and making sure that your eye doctor has checked all aspecets of your prescription necessary for aspheric lenses.
The difference between high index lenses will also be more noticeable if you have larger glasses.
As for opticsplanet - they are definitely not one of the super-cheap companies like Zenni. They sell far more than just eyeglasses. Customer service reports seem to vary quite a bit from lousy to excellent. Overall, more people seem satisfied than unsatisfied. What "awesome deals" where you seeing on their website? I see pretty typical prices and far from super-cheap.