DIY: Yes, I have the skills. Maybe I'll have to look into it before I buy, although I may or may not have time and money at the same moment. I will have time over Christmas break, just don't know what I can do at that point. Also I'd have to find a design that does what I want, which is low freakin bass that will modify my heart rhythm. I currently know nothing about how to do such things, but have no problem learning.
B&W: Tempting, and a tiny bit cheaper, and looks pretty/good specs. They don't have an oak finish though...Maybe my dealer has one though I can hear. I hadn't even thought about the 700 series, just assuming they'd be more.
Room: Attached picture. The HT space is about 10x10, but open to the rest of the common space in the house. Kitchen directly behind, 8' ceilings raising to almost 10 at the midway point between the HT room and the other living room area. Like I said, I've had no problems with output. Even the Velodyne will vibrate every window in the house with those dinosaur footsteps from The Great Fantasy Adventure Album.
Doubles: At the moment, there is only space for one box sub. I was thinking about the cylinders too, but there is no earthly way to put one in there with the other things that are already in place. It would have to go in the next room or something.
But then hopefully I'm buying for the future too when I can get out of this house which wasn't really built for such purposes. Thanks for the help so far!