compare high power mosfet for high power load
Question is, can you keep the FET within it's SOA range ?

The package by itself does not matter ! What matters is, can you keep the FET's junction below a certain temperature so that it stays in the SOA ? It is always easier to spread the load between as many FETs as possible to keep things cool. 

Also, these FETs are made for switching, so Rds is either as high or as low as possible. They might perform terrible when you try to keep them at a predetermined Rds because of their high K (Ids / Vgs). Note how that K I just mentioned is not mentioned in the datasheet (for the Fairchild one anyway) !!!!