rear speaker placement advice

[lunchbox]

I'm working on a home theater upgrade and in the last few weeks have purchased the panny bd35, pioneer 1018, 2 Polk Monitor 50s, 1 Polk CS1 and 4 Polk Monitor 30s and an ED a2-300. I'm getting ready to set up the surrounds and I'm looking for advice on the back surrounds.

The basement room is 30 X 16 with 2 sections (divided by couch), 15 X 16 home theater and 15 X 16 play area for the kids. The main listening position (couch) is 11.5 feet from the front speakers. Looks like my options are to hang the rears from the ceiling 12 feet behind the couch or put them on the back wall 16 feet behind the couch. I'd like to put them on the back wall to maintain headroom and keep them from getting hit with balls, plastic golf clubs, action figures, etc. With them on the back wall would I still get good sound using the Monitor 30s? I know it isn't ideal but just looking for any advice or suggestions.