No matter what you put in, i would HIGHLY recommend getting a processor for it. I re-did my whole audio package in my base V6. JL speakers all around, amp, processor, and sub and it was amazing the difference. My opinion you will only get so far without processing. Also processing on my front speakers gave me a "L C R" field and can also "help" get something out of the back speakers. But since where they are mounted, there isn't much they can do besides "fill" in the back.
I won't try and argue that having a processor is never the way to go, but I've found that in most car stereo upgrades, unless you're going to spend 5k+ on speakers/sub/amp a processor won't really have a noticeable difference...I'm far from an expert on this, but I have friends who have put put in a processor and it doesn't sound any better than my setup using a sub/amp with passive crossover...When you are only using 2 front speakers as main speakers time alignment doesn't really matter that much...sure you get finer control over frequency and such and a few extra EQ settings, but idk I'm not convinced it's worth it. Feel free to tell me why it is though if I'm missing something.