Use the utility blades.
Should be the ones for the power torque. The shorter ones.
You do not need the lift so there is no point using the catcher type blades, it could actually work worse as its throwing the grass up and mushing it on the underside of the deck rather than throwing or sweeping it out the side.
The 4 blade disc is designed to help create lift.
Two blades is fine. Keep good blades on it and the only difference i think you will find with the 4 blade disk will be it will cost you twice as much to replace the blades when its time to change them.
3000rpm divided by 60 times 2 is a lot of chopping. Up to you if you want to times it by 4 instead.
