From what I understand a 4 ohm speaker will be more accurate than a 2 ohm .
You have enough power for either with that amp.
I would get the 4 ohm because of that and because it will allow more adjustment for the gain . With the stock speakers (the 2 ohms) There is no adjustment range for the doors at least they have to be set at minimum gain.
If you go through Musicar they will give you the right stuff.
All the right stuff.