If that is what you want then people may be able to offer some other suggestions. The SB12 may not be what you want, you might want to look at the PB12, it's more expensive but again from what i have heard the paradigm wont even compare to this. There may be some other options. One thing to think about is this - Paradigm make great stuff but they have many levels of quality, you are at the lower end of that quality. They also sell it through stores adding links in the chain to get that sub to you. Each person wants to make money as no one will work for free so you tend to pay more than with an internet direct company where they make the profit they want or they get the sub at the price point they want and it tends to be much more sub for your money as there is less links in the chain.
I'm not knocking the monitor 12, as i said i really like paradigm but i think SVS or someone else will give you more bang for your buck, plus unlike in Aus where i am you have the bill of rights with SVS. One last thing, if you want the type of bass that you will feel in your chest the monitor 12 isn't like to give you this as it is also sealed like the SB12 and that is why is suggested the ported pb12, it will offer that more.
I am no expert here, hell i don't even own a sub but i was going through the same process you are for the last 2 months until this week.