Check out the new Kicker KM6500.2 Tower speaker set up. The only issue I see is that those factory cans are loaded with a 6" driver I believe and the new KM6500.2 have a std 6.5 flange pattern. I need to do some checking, but I think they will work. http://www.kicker.com/km65002
Another option would be 2 pair of KM6250.2. Same MSRP, but not nearly the performance of the KM65002.
You will also need to factor in a new amp regardless which direction you go. If the factory amp powering the current set up is the zx350.4, then those current speakers, as well as the KM6250.2, will handle more, power and the ideal amp for the KM65002 is a 2 chnl producing 150+ watts rms x 2 @ 4 ohms such as the zxm450.2