As a former owner of the B&W 703s I can tell you respectfully the B&W CM4 is a bad speaker. I went from the 703s to Thiel 2.4 (no longer made several pairs on here used) and the Thiels made the B&Ws sound broken. I paid about the same price for both. New for the B&W and dealer demos for the Thiel 2.4s. I still have both these speakers around and others so these comments are not from memory.
Anyway shop the used market. You can pick up older $3000-$5000ish speakers used here in your budget all day long. klh model 5s have been getting great reviews at only $2000 new. I imagine a used pair would be a good buy.