Just an update, the main part of this conversion is the front plate and headgasket while the rest just falls into place so Rob is in the process of finding out how to have these parts available for those interested.
If you are interested and havent contacted me, pls do so so I can get back to him as his internet connection and usage is limited.
I was lucky enough to see the ins and outs of this conversion and must say its easier than I thought. This head can be used with carburettors if you use a megajolt jnr crankfire ignition system from autosportlabs.com
The ignition kit is posted to Oz for under 250 USD which includes most parts required except for a coil pack which can be sourced locally from a holden v6.
Otherwise efi is also very easy from factory mx5, 323, protege, laser etc.
The original sump is left unmodified as Rob cleverly worked out a simple way to make the front plate seal the front of the sump without issues.

Im planning on doing an A15 to use factory 78mm mazda mx5 pistons to suit the head, also r1 carbs and ebay headers modded to fit my 1000 coupe. This head conversion using mazda matched pistons makes it a non interference engine.