[400TT]

Your choice in QLD at the moment is wide and varied. This is what I think is still allowed.

Ford 302 windsor(needs to be late model EFI)
Ford 347 windsor(stroker found in TE50)
Ford 351 windsor(needs to be version in Saleen Mustang)
Ford 4.6 modular
Ford 5.4 Boss
Lexus(toyota) 1UZFE and it's variants.
Holden/Chev LS1, LS2 etc
And lots of other exotics...

You choices are pretty good in QLD. Have a talk to Warwick Harrison(Cobra Kits) and Peter Ransom(DRB) they will up to date on changes and requirements for QLD. Both of their kits take all of the above engine configurations.

Engine choice comes down to personal preference and what you want out of your Cobra. No one engine suits every builder.