i'd be wary of that unlimited iphone deal
http://www.pcmag.com/article2/0,2817,2414418,00.asp
https://www.google.com/search?q=Stra...=1920&bih=1032
also, if you are going to be out on your own i'd recommend a very solid phone and contract with full support.
that phone will be your lifeline. i'm on att and just renewed, got the lg optimus g pro, and my bill is $80, after all the taxes and shit, which will be added to your $50. att also has cheaper plans.
you don't need unlimited data, let your phone find free wifi, it's becoming ubiquitous. and it appears that straight talk network is ~3g