i don't know about the sound quality or the ease of use of that sony deck cause it's all remote operated, but it seems to have some decent features...
in my honest opinion, don't get speakers for the rear, especially if they're just going to be 4x6's... having ****ty speakers in the rear will take away from your beautiful CDT's, and will make your system sound worse than if you were only running front components...
SAVE YOUR MONEY, and don't get rear fills... if anything get the HD-62's (not the CF's) cause apparently the originals sound much better than the carbon fiber ones... with the money you save from not getting rear fills you can get a better deck, maybe an Eclipse, Alpine or Pioneer to name a few... new sony stuff isn't that great...
trust me man, I went from having ALL 4x6's in my 90' HB (JBL & Alpine speakers) to just running front CDT components and there is NO comparison whatsoever... 4x6's are the WORST SPEAKER EVER DESIGNED, and it doesn't matter who makes them cause they all sound like crap...
BETTER YET... get the CDT CL-641 3-ways and just run those up front... make kicks for your 4's, and mount the tweets up near the A-pillars, and the 6's in the doors. hardest part is making the kicks, but you will be glad you did it...
in terms of amps you will only need a 2ch amp cause you're not going to need to power any rear speakers

I have a memphis st-200, and i am really happy with it's performance... (
http://cgi.ebay.com/ws/eBayISA...18796) this amp puts out 100Wx2 @4ohms, and that will be plenty for your cdt's... best place to put it would be underneath your passenger seat, that way it is somewhat easily accessible to tune, but at the same time hidden from theives...
here are some other decent amps to look at:ARC audio amp (70W x 2 @4ohm) Sony XM2100g (100W x 2 @ 4ohm) PPI A300 (75 x 2 @ 4ohm)
they might all be old, but a lot of the newer stuff is **** compared to how it used to be made...