Mt household has one of each, Kindle, iPad, Nook.
Wife likes the nook, it is easy and has color - in my opinion comparible to the Kindle.
I used a Kindle for a long time. Good battery life, easy to download media, but does not have the extra features the of the iPad.
On my iPad I bought a low budget, low ram version - wifi only. I have wifi in my house, so I connected it. Low cost. I can take it on the road, surf FABO,FBBO, FEBO and all the other sites with wifi. I downloaded Kindle app, and can have the same features as my Kindle. It is easy on the road and a good companion. Drawback, sucks battery life faster than Kindle, reading in direct sunlight.
Other cool thing with iPad, you can synch what you are reading on your kindle with other devices, you can download apps such as Zinio to read other purchased media such as Mopar Magazine, Dragizne, or plug it in for Diagnostics on your Mopars (if you have that feature with your ride).
Buy the iPad, you will be much happier - You dont need the super charged version, look on your local Craigslist, usually find someone trying to off load one. Be wise though