No,
Thats not the reason you need a new SIM card, they need to get you a new SIM card so you can use there service. Each service provider has a special SIM card, they are for (I think) telling what plan you have, therefore you cannot use the same one while changing between providers.
http://www.metropcs.com is the site for MetroPCS and it shows more cell phones other than Kyocera you can order!
Hope this helps,
Derek