The Calculate Value tool can be used to get the field type. You need to write a little python function.
expression:
GetFieldType(r"%Input table%", r"%Input field%")
code block:
import arcpy
def GetFieldType(tbl, field):
flds = arcpy.ListFields(tbl, field)
ftype = flds[0].type
return ftype
You can then connect the output of the Calculate Value tool to the data type input for Add Field.
Unfortunately the above code will return "Single" instead of "LONG" - I am leaving it to you to map the field types to the keywords for Add Field.
You will also have to build to appropriate expression for Calculate Field to copy the data over. This is most easily done using another Calculate Value tool.