I've got a text area that may be 30 figures long, nevertheless it is capable of around 2.000 figures.

For "future safety", it might be nice if the new column could support until 3.000 figures. I believe the typical size this area is 250 figures.

Which SQL Server 2000 data type 's better to increase performance and disk space?

Do you want unicode or nonunicode data? Use either varchar(3000) or nvarchar (3000). Avoid using text or ntext because they become problematic to question or update.

To create for average length will not make any sense.

In case your area will support 3000 figures, you need to most likely make certain your datatype will permit something which large. Design based on your maximum, not your average.

This seems like an ideal situation for VarChar. Are you currently doing any indexing about this area?