What is your actual requirement? Don't go for something that you don't actually need. If your requirement is 50 MB, go for a plan that provides that. Even if you get 50 GB for the same price the former will be more reliable.
Unlimited webhosting does not exist. This is a rule. Have a look at A2hosting.com: they have affrodable packages and support PHP5xx.
Unlimited bandwidth - RAM limited and in this case you won'rt make unlimited bandwidth never.