5.7 Hemi Heads source

Hi Guys,
Does anyone have suggestions for a good supplier of rebuilt 5.7 Hemi Heads? I would be looking to purchase from someone that does not require a core to be sent in exchange as I am in Australia and don't see my self shipping a set of old heads halfway around the world. Sadly it turns out that the heads that came with my engine are not up to scratch and I have decided to start over. Appreciate any suggestions you may have.
Ron