Datatype for large UNICODE string storage

Could someone out there tell me what datatype to use for storing large
amounts of unicode string data in PostgreSQL?

I.e :

In SQL SERVER I would use :
CREATE TABLE BigText
(
MyID NVARCHAR(10),
MyText NTEXT
)

In ORACLE I would use :
CREATE TABLE BigText
(
MyID NVARCHAR2(10),
MyText NCLOB
)

In DB2 I would use :
CREATE TABLE BigText
(
MyID VARGRAPHIC(10),
MyText DBCLOB(1M)
)

In PostgreSQL I would use :
CREATE TABLE BigText
(
MyID NCHAR VARYING(10),
MyText ??????????????
)

The maximum I would need to store is around 1M.

Thanks in advance for any help given.

Andy.
ahm(at)exel(dot)co(dot)uk