There is no alternative to the 2 step scenario.
You cannot invent your own movement types that combine the function of two standard movement types.
If you look into OMJJ then you have only the option to copy an existing movement type if you want a new movement type.
This is because there are settings to the movement types which are not changeable through any customizing transaction. If SAP has not foreseen such scenario in their programs which depend on those settings then you just can't have it.