Get the dual 4 ohms so you can wire them into a 4 ohm or 2 ohm load. But with the 500/1 it doesn't really matter because you get 500+ watts for any ohm load between 1.5 and 4, and any of the 2 subs you are thinking of (2,4, or 6 ohm) can be wired to have a load between 1.5 and 4. I have 2 W3v2s with a 250/1 and they bump, but are a little underpowered. And that 500/1 amp is definitely built for those subs. Get it!