Hello!
This is my second post so go easy on me!

I recently picked up a Bryston 9BST Pro so that I could get some better sound from my center channel. I sold my Nad 2ch Preamp and have been using an older surround receiver's pre-outs until I eventually get an entry level audiophile surround preamp or receiver (most likely Nad.)
I will be running a 3 speaker setup (L - Centre - R) setup, so I will have 2 free channels on my 9Bst (5x 120w @ 8 ohms; 5 x 200w @ 4 ohms.) I'm trying to decide whether I should bi-amp my centre channel or L / R speakers.
Here are my speakers:
Polk LSI9 - 4 ohm bookshelf speakers - rated for 20-200w
Polk LSIM 706c - 8 ohm center speaker; rated for 20-250w
Here are my options:
A) L and R bi-amp (technically up to 400/speaker @ 4 ohms); Centre with single amp (120w @ 8 ohms)
B) Centre bi-amp (240w @ 8 ohms); L / R single amp (200/speaker @ 4 ohms)
Option B seems like the right choice on paper, however people say that 4 ohm speakers are hard to drive, however I don't really know if this matters. Any tips are welcome.
(ps. I've done some reading on ohms/current, however I'm still a novice..)
Thanks for looking!!