Moose,

Take everyones advise and go with speakers that fit the holes. I have a system in my Tahoe with 4 MBQuarts, 3 10" subs and a unpowered head unit with 2 amps. This system will make anyone smile.

Be careful with the Infinities if you are putting them in the door. Once they get wet they are trashed. If you are worried about water you can put some QLogic Kick panels in and fill them up with the MBQuart speakers.

Size is not everything unless you are talking about the air you can move with your subs. The bigger the speaker the bigger the boom. I do not recommend ported boxes. Get a box with the speakers showing and your hair will stand up when you through some Kid Rock in the CD changer.

A good unpowered head unit, Changer, amps and quality speakers is the way to go.

 

Is there anything better than Infinity? (obviously there is, like JL audio and stuff, but what is the best and who makes it?)

 

The "best" is a little subjective. A list of top of the line, money no object components:

Adire Koda
a/d/s
CDT
Focal
Orion HCCA
Rainbow
JL XR (bargain at ~$225ish)
Image Dynamics
Alpine SPX (bargain at ~$235 for the 2 way set)
MB Quart (their midline and up)
Infinity Perfect
Diamond Audio
Dynaudio
Oz Audio
Phoenix Gold Titanium
DIY brands (scan speak, vifa, morel, etc. look at partsexpress.com or madisound.com) The best bargain, if you know what you're doing.

Which of these is the best, really, depends on who is installing it. Install is key. Any of these will sound phenomenal. General consensus, though, is Rainbow or Dynaudio. Don't ask for the price, though...