what kind of three phase full wave rectifier should we use?
I think this is all you need to know.

If you are using a Y output generator (rare) then you'd select individual Diodes.

If you are using a Delta generator (most common) then you could specify a block type 3 phase rectifier such as this.
Notice here that the maximum DC current is specified for 120deg conduction angle per diode pair.
 When it comes to 3 phase rectifiers you will also notice that there is a tendency to use high voltage avalanche diodes, so it's often cheaper to get 1000 - 1200 V devices than it is for 200 -300 V devices at any given current rating.