I would steer clear of Churn's idea of a "modest" AOR.... That is still a bit aggressive for someone in your situation. Since you are a student with minimum income you need to sit down and figure out your monthly expenses and determine what you can realistically spend on the cc's. Yes, there are ways to boost this (see manufactured and/or accelerated spend), but you have to be comfortable doing stuff like that. You don't want to get stuck in a position where now you are paying interest on your purchases because that would quickly negate all of the points your earn.

I'm not sure what your tuition situation is, but if you can pay for it or your books out of pocket you can include that in your projected costs. You might even push out your AOR a few weeks just so you can include the the spring semester to meet minimum spend (several cards are spend $X,XXX in 3 months but you need to give yourself a week or two buffer to allow it to post to your account in time).

All that being said, I would go with one of the Citi AA cards (check the wiki in that thread as there should be one with 30k points for $1500/3mo spend). OR get the personal Southwest card (50k points for $2k/3mo spend). And then get another Amex as it will be backdated to your PRG open date. Even though its not a "travel" card, I'd look at the Blue Cash Preferred or Everyday. BCE is a no fee and has a lower min spend but it has less benefits and bonus cash than the BCP. If you get the BCP you can always downgrade it to BCE at the 1yr mark. Check the web for the best offers on these (should be $250 for BCP and $150 for BCE). If you read the thread on the BCP you will see that you can buy giftcards at grocery stores and end up with 3-6% cashback on the first $6k spend annually. And you'd get 2-3% cashback on gas if you have wheels to get around in.

Once you get some additional income to justify your spending ability to the banks you can then "move up" to the better cards like the Chase Sapphire Preferred ($3k/3mo min spend), or Amex SPG ($5k/6mo spend).