use ir for both.  and setup the ir routing of the nevoconnect so that each cable box is controlled via different ports.   in the software you will need to have two seperate devices that use the same set of ir codes.  just name one device as "cable box 1"  and the other as "cable box 2"    then route the i.r for cable box 1 to a different port than cable box 2.   if the cable boxes are close to each other, you may need to put some type of boot over the emitter so one doesnt interfere with the other.