Well I'll answer my own question here. The Benelli M4 uses a Mobil style choke and from what I have learned most any modern/mainstream Benelli choke tube will work including the extended CRIO chokes. The ex-long CRIO chokes are apparently just going to look goofy.
George Trulock of Trulock chokes was a big help and provided me with the part number of his choke that best suited my request.
Last edited by TDMax; 01/24/13.
