Help me choose best IEMs for listening to rock (rs 500)

Hey ppl,
I'm planning to buy IEMs and my budget is max. rs 500.

I mostly listen rock; thrash (early metallica), melodeath (CoB) and the like.

Ive researched and found these the best in my price range:

jvc marshmallows
soundmagic pl11
sennheiser cx 200

So which one's best for listening to rock (esp. metal)??
What characteristics should one look for in IEMs best suited for rock??
Are there any other good IEMs available in this price range??