The kicker upgrade was worth the money on a budget. Taco tunes has some good system upgrades and OEM audio plus but they are spendy compared to the kicker upgrade.
I did the OEM Audio + in the wife’s 4Runner. I went that way due everything being -lug and play, install went smoothly and love the clarity of it. Depending on how the Taco is when I get one, I may do it again.
I did the kicker upgrade and with the Entune radio they sound really good. make sure you upgrade the tweeters with the kickers also and you can find a set of tweeters for a Subaru that will fit just fine. crutchfield is the best place to get the front and rear speakers and search ebay for amazon for the tweeters