Hey guys, I couldn't find much on this but figured others would love some help in the future. I recently installed a remote start kit on my 07 v8 and wanted to share how easy it was and leave a link to the kit that I ended up with from 12 volt solutions
2003-2009 Toyota 4Runner Plug & Play Remote Start Kit | 12Volt.Solutions .
This is a plug and play kit that was super easy to install with videos to guide you the whole way through. It does not program into your factory key fob but for the price and ease, an extra little remote is so worth it. You can also get an extra wiring harness and app module for an additional $200. I got my kit on a Black Friday deal for only $270 compared to the normal price of $400.
I originally bought a kit off of amazon that was $150
Amazon.com: MPC Complete Add-On Remote Start Kit for 2003-2009 Toyota 4Runner - Uses Factory Remotes: Automotive but decided to return it in the end after spending hours banging my head against the steering wheel with lack of instructions and trying to find the correct wiring diagram. If you feel up to the challenge I think this is a good option as it uses the factory key fob, but be ready to do a lot of wiring and guess work with the instructions.
If anyone else has a recommendation for remote start kits feel free to post here! I found in my research that these were the two cheapest options out there.