Help on Subwoofer Selection

[PaniqL]

Im in the process of Designing my Dedicated HT Room.
Its VERY Narrow about 7.5ft and 20ft Long and not sure what Sub(s) To get.

I Have decided to go with Klipsch Speakers and am certain on

RF-82 x 2
RS-62 x2
RC-62

and Sub Matching them would be a SW-112.
Is this Sub good for my room?

Or should i get a better one or two.

Im Probably going to have it behing the screen with the FCL Speakers.

Should i have one at the back as well?

Thanks