Actually... only the radar detector is legal in your state.
You may have the radar jammer confused with a laser jammer.
Laser jammer laws very from state to state; Wisconsin is one that allows them. Radar jammers however are a different story. It's a federal felony to possess, operate or sell radar jammers in the US.
Read
this.
In terms of detectors; the V1 and the Escort X50 seem to be the favorites.