Need help customizing Interior

I'm looking to put a 5 inch LCD screen in my car. Does anyone know where I can find them with out spending an arm and a leg. I want to connect my old PS1 to it. Another ? What is the best 8 inch speckers for a average amount of money. Or 10's. I have around $500 to spend just on speckers. I really don't want to spend any more then that. How about Amps. How much should I spend if I only got 8's. Would a 400 watt amp be alright for 8's. Remember, I only make $5.15 an hour.

I'm not sure if you have Fry's Electronics stores out there, but I was able to get a DVD & LCD setup for $300 or so. The monitor by itself was $99!