I have a Kenwood KDC X396 deck and am debating between 2 sets of speakers:

1.)
2.)

I listened to both of these at BestBuy and definitely noticed the Kenwood's gave more power and bass. I felt like they provided a fuller sound. The Kickers were very crisp and clear highs. Overall I think I like the Kenwoods better.

Since they will be powered from the deck itself (not an amp) is it better to go with speakers of the same brand as the stereo?

Other thoughts, suggestions, advice?

Thanks.

Brand wont really make a difference.

Do you know if best buy uses standalone amplifiers for the speakers, or are they powered off a head unit as well?

I have some really nice Klipsch floorstanding speakers that sound AMAZING when properly bi-amped, but like straight crap when they are connected to a cheap receiver. YMMV though.
Usually I say go with what sound best to YOUR ear. Sound perception is a very individual thing.

I would go with the Kenwoods simply because they are a component speaker. Coax sucks IMO.

Do you plan to run an amp? If so which one? Then match the RMS power per channel to the RMS power per speaker. Also consider dynamat behind the speaker when installing.

I do not plan on running an amp, just off the headunit. This is also how they were set up at BestBuy.

Get whatever sounds better to you. If you listen to your music really loud, and end up overdriving your hu, you will need to amp them. Secondly, I'd mount them on mdf rings.

I have two sets of the Kicker DS-65 (the series before the CS) 6.5' co-axial speakers that are rated at 150 watts. They can get very loud without an amp without distorting on the highs and mids, although the bass definitely won't keep up. I tend to tune my system so that the the subs carry the bass and the speakers take care of the highs/mids. It's helped a lot with sound quality. Looking back I should have gone with components instead for what I wanted but at the end of the day my Kicker speakers have kept me pretty happy.