Rumors have the lit Kindle coming out this summer. I have a cover with a light, works great, so I’m not interested in this.
To the OP, the Kindle Touch is a good choice. I love reading on my Kindle outside, it has less glare even than a paper book. Since you have an iPad I’d recommend that you use that for reading PDFs with charts or graphs. The Touch will handle converted text-only PDFs fine. Unless you plan to buy books on the spur of the moment on a deserted island or don’t have wifi at home, don’t bother with 3G. The ads aren’t intrusive and if you get the ad supported version for cheap and don’t like the ads, you can opt out by paying the difference to Amazon later ($40), so go for the ads.