Not sure about the RE SE b/c I have never heard them b4. A lot of people like them a lot tho. However, for the Kappa's, they get fairly loud. They can take more than 350wrms too. You could easily give them 400wrms. I guess that RE SE can see more than 600wrms too...
Which amp is it? Is that 600wrms @ 2ohms?
Yes, your right on the wiring. 1 4ohm DVC sub can be wired at a 2ohm load.