KINDLE
This is the best e-reader. I would recommend the 6" Kindle IF you are only reading ebooks. I would recommend the Kindle DX IF you are reading ebooks and PDFs that are in single columns without tables (in other words, uncomplicated formatting).
The Kindle has wonderful usability, and is easily one of the best-designed gadgets on the market right now. A kid or a grandparent could pick it up and use it with only a few instructions. It may not be as pretty as other devices, but it is definitely usable and durable.
Battery life is fabulous. I am a frequent flier, and for international trips I always bring my DX. Sometimes I can go the entire trip (both plane rides and time in between) without a charge. That is cool.
The memory is capacious. I have hundreds of PDFs and books in mine right now. I doubt you will run out of space, and you certainly have enough space to hold the books you might want to read on a trip. If you have your computer with you, you can move files around quite easily. In addition, you can access your Amazon account from any country to download books, so you don't even need to have the books you have bought in your device. In other words, you could purchase every ebook in the world, have that in your Amazon account, and just load in the ones you want to read (obviously, before you get on the plane). You have a Touch, so you can give this a try. Lots of free books are available.
The Kindle has drawbacks. Email and web browsing work in a pinch, but frankly, I think it is an unpleasant experience.
The Kindle doesn't do so well manipulating PDFs. Zooming and jumping around (in reference works, for example) is unpleasantly slow.
The Kindle has awful non-English support. You CAN read other languages, but a lot of times ebooks don't exist for it, and you cannot input foreign languages, so no searching or annotations will be possible. In addition, Amazon (like other companies) has to abide by international laws, and unless you have a credit card account in the US, you may not be able to access the full range of books. Try this out with the Kindle app on your iPod Touch to see what I am talking about.
IPAD
This is the best all around device. You already have an iPod Touch, so you know what I am talking about. Reading a book on the iPad is the same as with the Touch, but with more screen space. Glare is the same with the iPad as it is with the Touch (I haven't personally found it to be a big issue). The iPad is really good at accessing all book formats (so you can use .epub without having to convert files) and it has full language support. Chinese is no problem.
The biggest drawback, for me, is the battery life. It is simply unable to handle an international flight, and you will probably want to bring along an external battery if you are traveling any significant distance. Remember, it isn't just the plane ride, but sitting in the airport, riding the trains/planes/cars, etc.
SCHOOL
I use the iPad for school (I am a graduate student), and it has been a huge help. I also use the Kindle DX for reading some stuff, but a lot of my PDFs are of medieval manuscripts (handwritten Chinese), and the iPad does a better job of handling these. I highly recommend it. Basically, I have thousands of articles and books (I have scanned most of my personal library into PDF form) with me all of the time now, and that frees me from having to spend time in the library, or carry around books. Here is my workflow:
https://forums.macrumors.com/posts/12564519/
Perhaps your parents will be more impressed with its education potential