Sheath is sheath, you don't need an exact match, but you do need to bond it through. I've never used the closure you mentioned, but the Serviseals have a very easy bonding system and are on the same principle with the grease filled for water proofing, personally I wouldn't use a closure that just had the "snap-in" bonding connections. I would think there would be places around your area that sold buried drop by the foot.
