Best way of parallel wiring two alpine type r's?

Hello, I have an Alpine MRP-M1000, I am getting two Alpine Type R 12"s, and would it be better to get the dual voice coil at 4 ohms, or at 2 ohms for the sub's? Also, if I set both subs up to it, would the RMS be split in half, so both get 500 RMS each?