Short Answer you have to select all the different item types individually (e.g. Serialized Inventory Item, Sales Tax Item etc)
Long Answer Transaction and Items are not actual record types in Netsuite. Items is just an abstraction for the combination of different item types which is not available at every customization level. For a complete list of item types see
https://system.netsuite.com/app/common/item/item.nl https://system.na1.netsuite.com/app/common/item/item.nl