Well, I think I'm just going to go all out on the main panels, and use a Lambda 15" and a B200. No highpass, the subs will "augment" at the bottom. I've discovered I can get the B200s locally, and I've been, ah, hoarding the Lambdas for years. It was only when reading some recent threads here on AC that I realized what I needed to do.
Kevin's new tweeter looks interesting too, if it really can be crossed at 1k.