You are out of luck I'm afraid. There is no dump and load between different page sizes; page sizes are global to the ASE instance (so all databases in the same ASE must have the same page size); and page size cannot ever be changed.
You have two options:
1) As you say, create a 2K page size ASE and load your database into that, or
2) Do some kind of per-object creation and data transfer.
You have a few different ways of implementing the second option but they more or less boil down to the same thing: reverse-engineer the source database, apply scripts to the destination database, and then transfer data table by table. This is fussy and complicated but not actually very difficult, with many Sybase and third-party tools, some free, some pay-to-use, that will do some or all of this for you.
