Kicker upgrade.. sub or amp next?

So I started by upgrading my tweeters. I liked them enough so I ordered kicker CS speakers for all four doors and DynoMat alternative.
Now that I have all of them installed I want to order the kicker key amp. And kicker self powered subwoofer.

Should I install/buy one before the other?
I am considering waiting, until I can buy both. And installing everything at the same time as soundproofing the floor..

 

As an installer and from personal experience, most people opt for the subwoofer first. It adds a lot of fullness to your music. The amp is awesome and is definitely worth adding on, but the sub gets you more improvement for most people. That being said, if you value clear and loud over some extra bass, then by all means, add the amp first.

If it was me, I’d do the sub first. Or like you said, do it all at once since you’ll have the truck town down anyway.