If the OP wants to replace the Cable used for the PIB - 1, the method when used will add one more set of connections and disruption in the signal path.
Causing this condition is usually one that is avoided and attempts are made to keep the connections to the minimum required.
If this is the only option the OP is considering, a Pure Copper Zavfino DIN Plug and the Chassis Mount Pure Copper WBT reduced eddy RCA's will be a good start for the connections.
These parts 'could' be attached to the box, which will remove the need for the length of cable to be utilised. The additional Space that may be required under the TT to achieve this would need to be addressed.
A length of Cable with PC Triple C or D.U.C.C Wire will be a cable worth experiencing, if the Cable has to remain used with the box, either of these Cables will most likely be kept and expanded on in use as umbilical's at other interfaces.