All the three models now available in the US have 5 inch screens, being powered by Qualcomm Snapdragon and MediaTek processors, with prices that start at $279.99 USD.
http://www.notebookcheck.net/Sony-Xperia-X-Xperia-X-Performance-and-Xperia-XA-now-up-for-sale-in-the-US.169465.0.html