Feasibility: semi-autonomous (programmable) line following RC car

Hey all, new to the forum (and anything of this topic in general) and have an idea that I'd like to make reality. I've done a lot of searching around for the ideas that I have in mind, but was hoping to get some answers for a little bit of everything all in one place. I really just want to see if it's all possible with Arduino boards/shields, and where to go from the drawing board.

Here are some of the specs needed...

  • Line following (array of IR sensors)
  • Speed control/monitoring (to control acceleration and speed up to 30mph [max] and the monitor for testing)
  • Programmable with user input from smartphone (app from iPhone App Store/Android Market)
  • With this, would need it's own Wifi, like what the GoPro does
  • PID controller to tune for minimal corrections while on straight line and turns
  • Hooked up to an audio device (something to beep)

What Arduino board would be best for doing these things?
What shields might I need?
What would I still need for the car? With the Arduino, do I need anything besides servos, batteries, and the motor?
What the heck am I getting myself into?

I have some programming experience with Matlab/Simulink, but I know Arduino has a different language. My programming skills aren't that great but I can learn as I go and ask dumb questions when needed. I'm really starting from scratch on everything, so any help is appreciated!