Great Post that your Link answers your own question, I believe. First off Your Nitro is equipped the same as mine with black leather (R/T) seats that uses Dark Slate inside trim (DS) that looks black. Your Link list # DB complete assembly made up of # 3 pieces (8) 1CG951DVAJ. Your picture looks the same as my Nitro flaps. You must have been hard on those to break?
I will look around as you have already, but it appears you must purchase the complete assembly of two flaps and the base. Great that it is even available new now-a-days. Other option would be to find one in a wrecking yard used. Don't think there would be issues with a used one and should be less costly.
Good Luck and let us know how it all works out for you.
Again great post!
P.S. All Nitros are the same 2007-2012
Nitro Year: 2007 (1 of 91,815 sold in 07)
Nitro Model: R/T 4X4 Stone White
CAT-BACK Exhaust, CAI, Projector Head Lamps
Fully-Equipped w/all factory options