Free Car audio what should i get?

Congratulations!!

I would go with a Pioneer head unit (get one with pre-amp (RCA) outs so you can run an amp to to power your speakers, and either Pioneer, Kenwood, or Clarion 6x9's in the rear deck. That is a simple install and can be removed without too much trouble. It is also expandable if you want....

If included, I'd opt for an amp to push your speakers and one for a sub... depending on what you want and what all they are giving you!

I apmost always run an amp with my speakers because contrary to popular belief, too little power will ruin speakers faster than not enough power.... with too little power, you end up "clipping" the power outputs on the deck pr amp and heat up the voice coils in the speakers and can ruin them.

Do yourself a favor though, build some boxes under the speakers so they are enclosed. You will get way better sound out of them, better bass response, and they will handle more power and last longer. Basic rule of thumb with speakers, the max wattage ratings are if they are in a box... that drops to around 25% if they are installed open on the back (like in a door or in a package tray).

I put a system in my wife's 68 Mustang... did 6x9 in the rear deck (built boxes underneath) and hung an amp in-between the speakers... works GREAT!

PS. I do not do this for a living but have done lots of car and PA system installs and have run live sound for bands, church, etc for over 30 years.