Polk speaker configuration from 5.1 to 6.1/7.1

I currently have a klipsch speaker system consisting of a pair of sf-2 floorstanding, sw-12 subwoofer, ss-1 surrounds, and a sc-1 center that I've been using for the past 5 years and now is the time to upgrade. I'm in audio sales, and after listening to polk, infinity, and jbl almost everyday I'm wanting to upgrade my 5.1 system to a set of polks (i get a huge discount).

I would appreciate suggestions as to what to get for 6.1 configuration, possibly 7.1. The problem is that one side of the room is open and there's no room to the sides of the couch to place bookshelf/floorstanding speakers.

This is what I'm definately getting:

pair of polk rti-10 floorstanding
csi-5 center
psw505 10" subwoofer

optional:
pair fxi-3 surrounds