Yes, Nokia 8110 4G is a dual sim mobile phone. You can use one 4G sim card in one slot and another slot will be on the 2G network.
No. Nokia 8110 4G does not have the wireless FM radio.
Nokia 8110 is 133.45 mm ( 13.34 cm) long and 49.3 mm ( 4.93 cm ) thick.
Nokia 8110 4G comes with 512MB RAM and 4GB internal storage. You will get practically unlimited storage for SMS.