A few ideas.
BG has a sub for $1,499 list (model 210i) that is really really nice. It has 2 10" firing drivers (Kevlar). Jamo makes 2 THX Ultra 15" models in that price ($1,499 - $2000) range that are killer. Two of my favorites. I put a Jamo D6 in recently for a releatively conservative, serious, and straight faced customer of mine. For the grand unveiling I played the Echo Game scene from "House of Flying Daggars". When the base hit, to my pleasant surprise, the guy looked at me and yelled (because he had too) "Holy ****! I can feel it!" Made me smile ear to ear. He was more than happy. King Kong really rocked as well. I can attest that the Jamo D6 or D7 will blow you up. You will not need two. No joke.
I'm a BG & Jamo dealer and can personally attest to them making great products. I have the D7 on one of my systems at home. I'm keeping it and that is a rare thing as I like to burn through demos faster than you can spit. I have installed and sold subs from other brands as well.The RBH 1010-SEP is a monster but might take up too much floor space in a room that size. If it were me I would go for the BG or Jamo with a lean towards tha Jamo. I promise.... you will feel it.