oghhh man, Ok 600 you say?
lemme think....Can't go wrong with Kenwood for a deck I'm gonna say KDC-2019 because it's the best sounding deck I've heard for that price...it even beats the low end Alpine's.
that unit has 2 preouts however you'll proably want to run a 4 channel amp and a sub amp so I'll try to find an EQ with a sub preout for you.....again I'll go Kenwood just because they sound great...the EQ I would use would be the KGC-4042A.
On to amps....shouldn't be too hard to find a good 4 channel and sub amp for cheap because the selection is awesome....just to be different I'm gonna say the HiFonics Apollo series Son of Europa 4 channel amp should be enuff....it'll do 50X4 and I've never had any trouble with HiFonics...so the power should be true...on to the sub amp...I'm goin with the Ultimate Titanium TA2700 because I've used it and it's put out tons of power..plus it'll look nice sitting next to that HiFonics Apollo

the TA2700 will do 200WRMS in to channels or 600WRMS in 1 channel and that's at 4 ohms..so take those power ratings and multiply by 2 if your running a 4 ohm DVC sub...because then you would be running the amp at 2 ohms.
I know were gonna be a little off on the price here but I'm gonna say you'll probably spend about 1000 to 1200 bucks but remember that this equipment is quaility stuff...
On to subs and then pricing out all this stuff.
I'd say you'd be happy with a pair of 10" subs with the power your getting from the sub amp...so I'll say Cerwin Vega HED series subs in dual 4 ohms coils....now to price all this stuff out.
Deck=$180-$200
EQ=$200
4 channel amp=$230
2 channel amp=$195-$200
Subs=$70 each.
Total cost= $970+ tax
hope that helped..if you have any other questions please feel free to ask.