For a radar detector i would highly recommend the Valentine One, no other radar detector can compete. It costs a pretty penny, but you get what you pay for, and its upgradeable too. Saved my ass countless times.
As far as kill switches, that's something i would do myself, the point of a kill switch is to have it hidden so NOBODY knows where it is. Even though they are a shop, you never know. It's also pretty easy to do, run some wire for whatever you want to "kill" and wire it up to a switch, piece of cake.