I ended up going with FlexPay T Mobile Basic Plus. I didn't need a contract or credit check so I can stop payments during the summer when I am travelling. I just came back from Canada and rang up $4.50 in roaming charges over 4 days (I am not sure if that is good or bad) but texts while roaming come out of my bundle which is amazing.^ The roaming rate in Canada is $0.69 a minute which is high, but lower than AT&T's $0.79 a minute.
Thanks again for all the replies
Cheers,