Ok, heres how it goes. any amp you hook up to that thing is going to make it work. That amp you have says 500 watts.. like that kenwood i had said 600, but it most likely wont put out that much, and thats 500 peak... so you'll fry the amp. Idealy for a W6 you would want the JL 500/1 amp. That is pretty much the best amp you can get and though it costs slightly more, its penny for penny worth every 500 watt.
My final point: that 500 watt amp you have WILL work, but you wont knw the difference between a W6 and a W3 if you hook either one up to it because that amp is good for a W3 but underrated for the W6- so itd be a waste of money to get the W6.
*** I am not a dealer, I have no certification in this department. I just know a lot on this subject and have friends who are dealers and certified.. but; Dont take my word for gold- go down to a GOOD audio place (not Circuit City or Best Buy- they dont hire guys that are certified), go somewhere like Tweeter or better and see what they say. Im positive you'll hear something very close to what im saying. (unless they want to make the money on selling a W6)