a "good" reciever depends on what you want to do with it. if your just going to be running it through stock speaks and amps, basically any reciever will do, however you need a digital converter so that it works with your factory amps used in the jbl system. the converter will set you back 70 bucks. so add that to the price. if your just running of the factory amps, the wattage of your reciever doesn't really matter. pioneer, clarion, alpine, even sony are all good and trustworthy names. One item that played a role in my descision was that i wanted a rotary volume knob. not just two little up/down buttons, and the sony fit my needs well. it hasn't upset me since i got it.
if you are going to want to expand (believe me, once you pop, you just cant stop) you need to look for a good amount of preamp outputs. four channels are plenty. its also good to find a head that has separate subwoofer preamp outs, in addition to the 4 others.
in summation, give your goals for the system, and we shall provid the answers.