I want to buy mobile from USA?

I'm planning to buy Iphone 5S or nokia 1020 from USA. Please answer my following questions!
1. Which one is better to buy Iphone 5S or nokia 1020 or anyother mobile you will suggest like HTC?
2. If i buy iphone 5S from USA will it work in India. I mean it will be unlock and i will get warranty? And will it work on indian telecoms like airtel, vodafone etc. ( same question for nokia 1020 or other u suggest)

please ans. My questions thank you.

HTC one

I know iPhone is gonna be costly in india even apple tried to lower its price. I'm too excited about getting a new iPhone.

1. I'd suggest you to iPhone 5s, if you really love to use apple technology. Other phones can give you more features and things. But still iPhone is better than all. Once you bond with ios, you'll never go back to android. If you don't want an iPhone or its costlier for you, then sony or HTC. I've use galaxy note 2, worths every penny even price got lower.

2. If you buy iPhone from US, you get the phone at cheaper price. Cuz it'll be contracted with AT&T or verizone (Us carriers) for 2 years. So you have to unlock it in order to use indian carriers. And it can cost you around 6000 INR.