Aram, a few things: 1) If you can't get to the bi-wiring right away, you should use a jumper cable instead of the connectors that come with the 100's, 2) I auditioned the Paradigm subs and wasn't too impressed since the bass seemed flabby to me -- though great for HT, and 3) You may not need much more oomph so a smaller sub-woofer, say 8 -12", might be just enough to do the trick so long as it gets down to 20Hz -- anything real big might be hard to match since you already have good bass. I own the 100's and found all that to be true, at least to my ears. Good luck. Remember that for frequencies below about 200 Hz, standing waves (which are largely dependent on room dimensions and either reinforce or reduce sound levels at various frequencies) make a huge difference so please be sure you can audition at home.