Probably not outside the SPS 40 array itself. But these cutters do have weight and space available for harpoons forward of the bridge and a Phalanx CIWS aft, and most likely a Searam CIWS upgrade in place of a Phalanx.
I agree with you that the SeaRam is the most logical and best way to go for the PN instead of other fancy expensive missile systems in terms of upgrading the ex Hamiltons armaments...