<p>Mmmm...usually, I'd advise you to take the one you'll (most likely) score higher on, but if you're feeling equally confident, I'd go with IIC since you're covered in humanities by US.</p>
<p>As far as which one is easier to study for, it really depends on you. I got the same score on both, but I had to work a lot harder for the 800 in math because I'm not as good at math. Literature is usually acknowledged as the subject test that's the most difficult to study for, but if you have a strong lit background, you shouldn't need too much prep.</p>
<p>You might want to look at the requirements of the colleges you think you might apply to. A lot of the colleges, especially the technical ones, require the math test.</p>