Need help picking speakers

[Huck]

Hey guys! I need some help in deciding what speakers to get for the rear spots. I know, I know. I've read all the back and forth about whether or not rear speakers mess up the soundstage in the car and all that, and I've decided I like having the sound all around me.

What I need help on is deciding what speakers would be the best and what speakers fit. I know the rear spots are supposed to hold 3.5" speakers, but I've also read a few threads where people said that they put 4" speakers back there. Can they really fit? Or at least, can they fit with only MINOR modification?

As of right now, the speakers I'm looking at are

Infinity Reference X REF-3002cfx
Infinity Reference X REF-3002cfx 3-1/2" 2-way speakers at Crutchfield.com

Polk Audio DXi350
Polk Audio DXi350 3-1/2" 2-way car speakers at Crutchfield.com

Sound Ordnance P-35
Sound Ordnance™ P-35 3-1/2" 2-way car speakers at Crutchfield.com

Polk Audio DB351 3.5-Inch Coaxial Speakers
Amazon.com: Polk Audio DB351 3.5-Inch Coaxial Speakers (Pair, Black): Car Electronics


Any suggestions? Is there another brand that's better that I'm missing? I appreciate your help in advance.

Just for reference, at the moment I have Alpine SPR-60C component speakers and an Alpine R SWR-12D4 Sub with a Kicker 400W amp. I hope to switch this out soon to the Alpine PDX-V9 amp to power my components.