sound system recommendation and question

So I'm looking to get some decent but cheap speakers for the SC. Right now I'm looking towards this setup since it seems to be a good deal.
http://www.onlinecarstereo.com/CarAu..._SPS-600C.aspx
http://www.onlinecarstereo.com/CarAu...e_SPS-400.aspx
http://www.onlinecarstereo.com/CarAu..._MRP-F300.aspx
Basically 6.5 Alpine Type-S component speakers with tweeters...but I can only fit 4" in the front doors and I'll mod the rear deck to fit the 6.5". My main concern is, is it bad to put the 6.5" component speakers in the rear deck, with the tweeters up in the front in the door window trim area? Everywhere I've read that the components go in the front doors along with their tweeters...but I can't fit that and I haven't really found any 4" component systems.
Then I'd be putting the 4" 2 way speakers in the front doors...would this setup be wrong? or just sound funky? and also is the amp necessary or is there no need since my head unit can somewhat power it. I'm just looking for crisp sound nothing to bump and vibrate the car and what not. Eventually I'll be upgrading the head unit along with a sub to fit in the stock enclosure.
Thanks I suck at all this audio stuff.haha
You can fit a 6.5 in the front with an adapter and some spacers.
As far as product selection goes, won't get much better than this
Phoenix gold rsd65cs
http://www.woofersetc.com/p6952/RSD6...ker-System.htm
Crescendo audio 1000c4
http://www.crescendoaudio.com/produc...roductid=17516
It's a 4 channel so you'll have a spare 2 channels left for a sub incase you ever get one.
The amp will do 125 x 2 for your front stage and 500 x 1 @ 4 ohms for a sub.



