I have a python 990 (same as viper 5900, made my the same company)
I think it works amazing.
Ive seen other systems that are two way, paging, spread-spectrum, and LCD screen that are not as easy to use, reliable, and as well built.
No matter what you are getting, directed makes GREAT STUFF! (re-enforcing atomic punk's post).
You can get a directed unit at tweeter (which just claimed bankrupcy IIRC), circuit city, best buy, and some small mom and pop shops with higher end gear.
What year is your 4Runner?
And do you know if you have a chip key?
Also, if your looking into remote starters, look at security systems too. If you do look into security, look at getting some extras, they offer things such as battery backup, extra sirens, tilt sensors, motion sensors, audio sensors, etc.