You know what, I checked again and believe this does include the J mount. It originally sold for $79.99 and is marked down to $22.50 (72%). It looks like I'm all set.
http://www.amazon.com/RCA-ANT751R-Ou...eywords=ANT751
BTW, I read in some of the reviews that buyers have experienced faulty transformers.
I could mount this on the southeast corner and tie into the existing cable box (which I am not using). And use the existing ground rod on that side.