Planning on upgrading the factory speakers on my 03 Lancer OZ.

Running off of the head unit (Clarion - 53Wx4/18W RMS)
Basically looking for the best "bang for buck"
I've read stock size is an oversized 6.5" or 6.75" - and i would like to avoid buying the $10/pair bracket off ebay/clutchfield if i could.

I've done plenty of research in the past week or so, and have come across these as my final choices:

1. Polk Audio DB651 OR DB651s ($70/pair)
Clutchfield Canada claims the DB651 do not fit.
Clutchfield USA don't claim the DB651 don't fit. =S

2. Infinity 629I ($70/pair)
I've read mixed reviews about the Kappas... anyone have any experience with these? will 2 ohms run off of my head unit properly?

3. Infinity Reference 6032cf ($65/Pair)

4. MB Quart Discus DKH116 OR FKA116 ($65/pair)

*Note: I have no car audio experience and will be attempting to install these speakers myself following the "how to guide" of this forum, so ease of install per speaker will also play a factor in my choice.

Any experience stories and/or help is greatly appreciated.