Yes, I have Kindle NT 4th gen. Depending on how you download them, will have different format, and ways to transfer.
Can read pdf. Current price around $200. just google la.
Software you need:
Kindle for PC
Calibre. (Install the apprenticealf.wordpress.com plugins for de-drm. Allows you to transfer e-books to other kindles and read on kindle if you unregistered your account on kindle.)
Buy ebooks from amazon.
Use hotspotshield first to mask IP so they won't block your account, you can't buy ebooks from Singapore cos of legal issues.
Kindle 4th gen onwards has wifi. So if you choose the option: "send to my kindle" it will send the ebook to your account registered on kindle. That's all actually. But again my account on kindle has been blocked repeatedly cos it connects online and checks IP address sometimes.
So, failproof method:
Choose the option: Kindle for PC.
Once the ebook is bought & downloaded, go to My Documents>My kindle content. You will find the file with extension .azw
Connect kindle with usb. Open Calibre.
Drag the file individually to Calibre to add one by one. the format should be azw3 on the side panel. If you select multiple books, may have errors.
Select the ebooks and convert to epub.
Click "send to device".