One point you might want to take into serious consideration. You do all this massive work and then throw it on the bed to discover that all that cool graphic motion is utterly lost! The way you need to view this is as a piece of wall art that hangs so you can stand back and view the apparent movement straight on. Almost all that motion is obliterated when you view it from above and at an angle. The contours of the bed also make sure your work on this one is lost in the ultimate use . Other quilts are cool, funky and 70's like without as much work-- (especially if that work is then lost on a bed)
If you want a big wall hanging that is another story. Yards of wonder-under and the suggestions given by others would accomplish it.