Ice Cream Sandwich doesn't require anything special to run. It is basically the same as Gingerbread requirements (a) 256MB of RAM and (b) a decent GPu. That's it. This basically means almost anything can run it. Ice Cream Sandwich hasn't really made its way into the public but based on everything available about it, it should be able to run well on just about any tablet currently being made including the Fire. I can recommend the Nook Color, it already has root, custom ROMs, an established community and developer support. If you meant to say the Nook Tablet, that is also a good way to go although at the moment it only has root and not custom ROMs. It is unclear at this time if custom ROMs will be available on the Nook Tablet.