240 is too harsh, the paint will fill in the scratches but you will require a decent amount of coats. 320 or 400 is my recommendation.

Primer: https://www.supercheapauto.com.au/p/...gment=1&page=1

Colour: https://www.supercheapauto.com.au/p/...cgid=SCA011004

Clear: https://www.supercheapauto.com.au/p/...cgid=SCA011004

Check out some of the threads by fellow forum dweller 'Phrozin'. He was a spray painter, he has done quite the number of kits and he swears by SCA (Supercheap Auto) branded spray paint when he isn't using an actual spray gun. He has pictures of kits he has finished using SCA spray paint, the results are pretty mint.