I have an International Kindle which I purchased via Australia. Amazon would not ship to China where I am living. For me it is perfect as purchasing novels in Xiamen or anywhere outside of Shanghai is extremely difficult. I download FREE books as I read a lot. Suggest download any book via computer then cut and paste into Kindle otherwise you will be charged using wispernet outside of the USA.
The Kindle 2 is an ideal size, 6 inch screen and most importantly is not backlit (a computer screen is backlit) and as such, not being backlit is not hard on the eyes. Naturally reading in the dark will require an external light. Reading in sunlight is great as no glare. Have a look at the Amazon site under the discsussions area.
I currently have about 25 books on my Kindle, but I delete them when I read them. Many people have thousands of books stored on their device. . Imagine travelling with one or two books in your luggage. They take up space and add weight. Travel with 20 or 1200 and what weight and size would be taken up. Why do I have 20? Well, "I can, so I have that many".
The iPad is bigger, heavier and has multi functions. It has its place if you are after a multi-functional machine and twice the price (approximately).
If you want a book reader, then I personally would not go past Kindle. I looked at Sony but they did not sell internationally and did not want to take the risk of buying one only to find that I had problems outside of the USA in using it.
Good luck in your choice. Contact me if you want any specific info or as i said, check the Amazon site.
Best wishes