best 2 channel amp/comp set under 600?

Alright here's my setup

2004 Mustang GT Coupe
2 Kicker 12" Dual 4Ohm CVX's wired in parellel
1 JBL GTO 14001 which is supposedly 1500watts rms @ 2ohms w/ less than 1% distortion

Sony 4ch 60 watt rms x 4 @ 4 ohm amp (yea its cheap as hell)
2 Polk Audio DB 5 1/4" speakers rated at 45 watt rms @ 4 Ohm

1/0Gauge power cable running into a splitter split into a 4 gauge into the sub amp and 8 gauge into the 4ch

anyway what im asking here is what 2 channel amp/ componoet speaker is gonna be the best sound quality, and loudest treble for under $600 including the amp and speakers, i was reading the thread about speakers earlier and you guys say you dont like metal cones but i've heard alot of people with infinitys and i think they sound real good,i have infinitys in my home setup

infinitys are great it just depends on your preferance. if you like very "bright" tweeters then look no further then focal. they will scream your ear off. that being said you could actually get the higher focal set for about 500 and run it off the HU and im sure you will be pleased. or you can go with the infinity kappas which are awesome as well but need to be amped and match it with the 08 infinity 4 channel, forget the model number but its around 250 new. and the kappas run about 250 as well. so either way you will have good sound and can crank on ither speakers with not alot of distortion at all.

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Pioneer DEH-400UB
Kicker 150.2 mids/highs amp
MB Quart fsa 216 front stage
AudioPipe gd-6001 mono amp
AUDIOQUE SD 15S PREFAB BOX!
C&D Technologies Battery, 1500 CCA, 134 amp storage
149.5 DB's