Typical horn loaded sub issues are a limited (and peaky) frequency range and lack of extension. A horn has to be fairly large to dig deep. Don't be misled by specs. How is the 130 dB measured and at what frequency? In the port? My son has a sub in his van that will meter 148 dB at 34 Hz, but I wouldn't want it in my HT.
Bottom line is that you have a large room with multiple openings. In order to have decent output in your room, your going to have a lot of displacement and move a lot of air. A compact 10" horn loaded sub just isn't going to give you what you want IMHO. On the other hand, if it's cheap enough, go ahead and build it. You won't have much to loose and it will be a good exercise in subwoofer construction.