For the purposes described here, I would suggest a CSRB+.
http://www.paulcbuff.com/csrplus.php This will allow you to treat the speedlite as a separate light, which means you can group it and independently meter it. If you went with a standard CSRB, it would trigger from the CC, but only as part of the entire set up.
I think that speedlite has a PC connection on it, so no other adapters are required. However, if you prefer a 1/8" connection, you can get one of our foot adapters.
http://www.paulcbuff.com/slfa.php