Behringer is around $400. Yes, it is available. Clarity is around $3,000. Have not heard. Only two I know of. I own Behringer. Have owned several electronic xovers over many years. This is the best one I've ever heard - VERY transparent. Don't know it's in system to my ears. Would highly recommend. Not sure what you mean by "can they be used to replace ....." Yes, they are better than what is in all speakers except perhaps the electronic ones built into some speakers.
