Yes you will need adapters at least for steering wheel controls. You can hard wire the rest if you choose, but an adapter makes more sense.
Be aware that adapters do not power then antenna booster and usually the instructions make no mention of this. If you want to hear AM/FM radio stations do some searching on that. It makes all the difference in the world.
Hey, I was confused on what harnesses I need, I was looking to buy a Pioneer DMH-W2770 NEX headunit to replace my OEM radio. I do not have JBL or RDS on my 2004 SR5 4Runner V8. Thank you for your help!