Bean bag chairs

So if you read yesterday's post you saw that I am contemplating the idea of making a reading nook for my kids.  I thought that some bean bag chairs might make a nice addition to this nook, and might make a good Christmas present for each kid.

However,  bean bag chairs come in all shapes, sizes, qualities,  and prices.   If you were outfitting a reading nook for children ages 9-1 (the approximate age of my kids at Christmas), what kind of bean bag chairs would you get?

Would you get quality bean bags, that are more expensive,  but will last?  Would you go with cheap ones, that may hold up for a year or so?
Would you get them ones designed for the size they are currently,  or ones they could  fit in for a long time?

Any particular merchants or stores you would buy from or look at?

Any other thoughts or suggestions?