What you guys think?

Ok as some of you know i have a set of 15" AA Atlas subs. And i plan on making another 3.65 enclosure for the other and i have a good deal i can get a an RE SX for. Well i have an autotek MM 1000.1d and i was going to run it at 2 ohm for 700 to both subs. If i can get the SX you think it would louder or just as loud to put 1000 watts to the SX or 700 to 2 15's. I will be using the same enclosure so i will have one instead of 2. And if i can afford it later down the road i will get 2 SX 15's. ANd another 1000.1d amp.

Any thoughts.

i think the two 15s would be louder.