In just wanna torrent all the books I literally don't have the luggage space to haul back across the ocean
This is not the panacea you might think. The formatting of most books out there makes them insanely annoying to read on Kindle. Only about 2% are actually readable for me. You might think "Hey, i read text on a screen all the time", but until you try it, you won't know just how annoying it is.
S.H. - no idea about Kindles, but you can read damn near anything on iPad, one way or the other. .epub, .doc, .pdf, whatever. My experience so far has been: pay the damn $10 if you plan on reading the whole thing on an ereader, if you value your sanity.
Obviously, we're still in the early days of ebook piracy so the situation may 'improve'. Recent books I've downloaded have been much more iPad/Kindle-friendly. But, right now, the chances of me being able to toss out my entire bookshelf and replace with torrented files is zero.