For your size room, the 1.7i's are more appropriate. You will get a huge sound stage. I own the 1.6's and the original MMG's about the same size as the LRS's and there is no comparison in the size of the sound stage.
I use dual Martin Logan original dynamo subs because they are small (WAF). They are fast, musical and integrate seamlessly with the Maggies. And they just disappear. Take a look at the new Dynamo 800 and 1100. They are small and you can place them anywhere with a wireless module. My original dynamo's sound better than many more expensive subs at the time. However, if you want earth shattering bass then you will need larger subs.