Can you tell me if you think this is a good system setup. An alpine CDA-7892 HU, 4 Jl audio interior 6 1/2 speakers, a JL audio 250/1 amp, and a Jl audio W3 sub. Thanks

 

By the way, the sub is a 12

 

Yeah, JL Amps are AWESOME!!! They offer the great RMS ratings and plus they look good too. As for the speakers, I suggest getting either Kenwood 1/2s due to the super light weight of them. They are extremely light and have a real small mounting depth. No distortion what-so-ever!
JL subs are some the best sounding subs on the market too. They're cheap and are able to compete with the best subs out there. Sounds like your system is going to thump man! Good luck and take pic's of the install when complete.