TZR250-3MA
as in
I know, for a fact, from owning that particular beautiful beast, that is has a perfectly shaped ultra thin single-pass radiator in it, Aluminum though, But I am not afraid.
I went looken for it too, a while back, I guess the motorcycle community is still very much not on the information highways of today... your best shot would be your local cycle dealers.
you will however get some severe sticker-shock-whip-lash
these radiators are by no stretch cheap.