I also had a 3G keyboard one, but S got me a Paperwhite a couple of Christmases ago, and it is a lot lighter and easier to read. I loved the original one, but when I got it I don't think phone contracts were as likely as now to be unlimited, so now I wouldn't bother with 3G and just download to the app on my phone if I needed to, then put it onto the kindle when I was in reach of wifi. I have downloaded to it by tethering to my phone, but in the Lakes, not abroad
The Paperwhite ones are waterproof, so if you want to read in the bath or by the pool you can relax. Also, you can listen to Audible on them if you bluetooth them to a speaker.
Oh, and I wouldn't worry too much about the storage, as everything you buy is saved on Amazon, so you can add and remove things as much as you like. You can easily get hundreds of books on one, and in the unlikely event that you filled it up you can just shuffle them around a bit so the ones you've read go back to the cloud and you download different ones. I've filled mine before when I downloaded a million Audible books for reasons that make no real sense.