The rizr is a bit narrower, but the Sony Ericsson is more customizable once you debrand it. Google it if you don't know what I'm talking about.
Also, Sony Ericsson would be much preferred over the Motorola. Ask a lot of people that know about phones and they'll give you that answer.
DKY
It depends how small you are willing to pay for, but 2 free phones from what you listed? No way they will do that. I seriously doubt they will give you those phones for free. But it all depends on the salesman/woman you get. Most likely no. As for the smartphone question, most carriers allow you...