This is a long standing debate I've had with my brother. For some background, I've owned the following: iPad 2, 16gb, Retina iPad Mini 32gb.
Like yourself, I used it to read magazines, comics, watch movies, play games and all that stuff. The 16gb (really, about 13 usable) in my opinion disappears far too quickly, especially if you are the type who like to keep magazines on hand. The files range in size (assuming you are buying them through the Newstand app) from about 300 mb+.
Couple that with any music you'd like to store on the iPad (I don't) and apps, and you'll find yourself playing storage tetris with your apps/magazines.
Keep in mind apps for the iPad are bigger than they are for the iPhone, plus the fact that since Apple switched to 64bit processors, apps do take a bit more room if they have been switched over.
Currently on my 32gb mini (27.4gb actually usable) I have used 18gb, and it's filled with Comics and apps. I can't imagine going any smaller than 32gb in this day and age. Consider the following:
Comics - 8gb (mostly complete manga series)
DQ8 - 1.6gb
FFT WOTL - 805mb
Hearthstone - 661 mb
Also, pages, numbers, iPhoto (now all free with the purchase of an iPad) take roughly 400mb each.
What I would really like is 64gb, but that was too rich for my blood. I think you'll find that once you start using your iPad, you'll use it a lot more often than you had originally thought. I use mine for reading, surfing (my computer went untouched for 2 weeks when i first got my iPad), Youtube, streaming shows, taking notes and editing documents.
Also, Air vs Mini: When I had my iPad 2, I took it on a trip and actually found it to be somewhat cumbersome. While the Air is smaller and lighter than the older versions of the iPad, it is still a good size bigger than the Mini. With the mini, I don't think i've gotten tired holding it just yet. Plus, for the same price you can get the 32gb Mini or the 16gb Air. Using the Mini, I've never once thought I wanted a bigger one, but that's me having experienced the bigger version as well. The ultimate question comes down to the choice of colour...will it be white/silver or space grey....?
There is a certain...je ne sais quois about handling the Mini...it just feels right. Of course, YMMV, but the best thing to do is to try them out if you can.