I have had cheap detectors before, and they are NOT worth the money. The go off all the time so you start to ignore them.
I bought a Bel 630 I think, too lazy to run to my car and look. Cost was about $200 from Circuit City. Thing works like a CHARM, excpet I had to have it replaced once since I stopped making noise....Buy the WARRANTY!
Other good ones are a Valitine One, or a Pasport 8500, or any other high End Bels. I have also heard good things about K40's.
As for Jammers, Radar jamming is illegeal in all 50 states and carrys a HUGE fine. And places like Rocky Mount Radar etc, that say they jam, are a joke.
As for Laser Jammers, There are 2 good brands that I know of. K40 -Difuser, or a M-20 Blinder or an M-40 Xtreme Blinder. I had the blinders on my old car, until I got in a accident, and never put them back one....too lazy. Plus not many cops here have Laser, never crossed one yet, so I did not see the need.
If Laser is used alot where you live...get the Laser Jammers. Oh, it is 100% LEGAL to jam laser....its just LIGHT!
Best of luck, and remember detectors and jammers are NOT 100% perfect, and with Instant on Radar now, you can STILL get tickets. Trsut me!