good advise--thx99.99% run the Ford coolant. There is no holy water that will give you a cooling edge. The one and ONLY solution to better cooling is an upgraded heat exchanger with fans. Use the factory Ford coolant. Don't use straight water, or water wetter or any other magic potion.
It's exciting getting a new car and wanting to do everything at once but plan your steps carefully. Don't buy out of emotion buy with a plan! I noticed you replied to an ad for 2" headers. Why? Don't get yourself in a rush you will only end up wasting money. If you have a stock car right now, buy a heat exchanger or buy parts that will improve the performance and can also be used with a different blower. (SCT tuner, cold air intake, throttle body, midpipe etc. Headers should be one of your last mods in terms of power adders. You can do quite well on stock manifolds. Adding headers right away on a stock setup won't yield the best results, you want to open up in intake side and get more air in to get the most benefit from headers. And 2" headers is not your best choice.
Your money, your car, your choices. I am only sharing my advice.