I would go with the dual 8's and just bridge the amp for them. That way each will see 150 watts rms. You will have to get the dual 4 ohm versions and wire it like this:
How much were you getting the Eclipse for? For comparison sake you can get a breand new Pioneer Premeir DEH-P860MP for 320 shipped. That CD player will blow the Eclipse out of the Water. But the Eclipse is not bad at all, don't get me wrong.
I've used the Infinity Speakers a long time ago, not very impressive at all. If possible I'd rec. not buying any rear speakers at the moment, and use that money towards a nicer set of components and an amp for them.
You're also going to be limited to shallow mount speakers in the front. I pm'ed you a few links that will help on that issue.