Find the one that suits you the best. If you want a rewards card, then go with that. If you want a low interest rate, go with that one. Never select one with an annual fee and always choose the best card for your needs.
It doesn't matter that much. You can always add fund to your PayPal account from CC, and then use PayPal to handle all transactions. On the other hand, you can easily dispute a charge with your CC issuer than PayPal which is a big hassle in most cases. I would pick cash back cards for myself, because I always pay off the balance and pay no interest.
NONE!!! Get a bank of america credit card ---- better rates...less transfer fees..I just transferred my citicard balance to boa