Get the factory coolant, 23.00 a gallon mix it 50/50, its good to -35 or so. You'll need 2 bottles, you'll have a little left over, for emergencies.
Some times the factory stuff looks "orangy" too so dont worry, If you are worried, rinse it out with a hose and fill er up with your premix. Gently heat cycle the car 2 or 3 times, topping up in between, and your good.

 

Coolant capacity is shy of 8 gallons so if you drain it really well you will need more than 2 bottles or 4 gallons of mix.

 

I wouldnt try to DIY a total drain and fill, have a shop do it, should have qualified my statement. Even a water pump replacement doesnt drain over 3 to 4 gallons, unless you are really slow....

 

Thanks for the info. I'm in the same boat too. Does anyone here use Redline water wetter or Royal Purple "ice" to boost coolant effectiveness? Thanks.