Here we go again gump.
To get the great sound out of your system its all about "Front Staging" Which gives a front dominant sound like listening from a stage. I have been tweaking on front stage since my first car where the 1st speakers I dropped in were walmart duals
. Anyway step one is getting your highs and lows split which you have already done, but where are your tweeters sitting for your comps, because if you got them in the door your restricting the ability, you basically have a high end coaxial in your front door. Anyway for the rear mainly you would use a "filler" speaker AKA: Coaxials just to fill the void of sound in the back seats I have comps back there but the tweets are in the B pillar angled in the front lol so basically coaxials. People in my back seat get left out. So on a budget I recommend the filler.
Dash. The 3.5s will add more dynamic sound by being a coaxial. But they get a little tricky to tune if your as insane as me. But they are a good choice once you get them at the right HP-LP they deliver!
As far as speaker brands I saw you said kickers were backordered....eBay that 3.5s are cheap on there!
With your rear you can brand match with your kenwood I don't think it would be a idea you would regret for any reason.
Amps
If your liking you hifonics I have nothing bad to say about there doors amps they are not CEA compliant but it still never bothered me plenty of sound, and they are clear for the $
I wish they had this one when I was doing my old LT, Compliant Hifonics.
Hifonics GLX60.4 240W RMS, Class A/B 4-Channel Gladiator Series Amp
Kenwood KAC-2404S (KAC2404S) 500W 4-Chan Stereo Power Amplifier
There is a lot of options and if you need to go cheaper Im not going to hate on you, Your truck your rules.