I have to agree with above ^^ I would say that any pre-paid low end phone would do just fine for the price, and I found even my Samsung Galaxy Ace had some awesome ROMs (not the greatest device but any custom ROM made it much better).
The only other possible option is a tablet, but I'm getting the feeling that portability is more what you are looking for and a 7 inch tablet isn't always the most practical to carry around. Unfortunately I don't know of any iPod style devices powered by Android other than the Galaxy Player (which flopped so there wasn't a next generation). The only possible other device for you could be the Samsung Galaxy Camera (the first gen comes in 4g enabled versions) however this device is more specifically camera oriented so I don't think that it would work well either.
Best bet is most likely a prepaid phone because most cellphones these days are replacing the need for multiple devices. Hopefully this helps and I wish you good luck.
Sent from my Nexus 7 using xda app-developers app
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