Neither one of those bottles (your pictures) are pre-mixed. You have to mix 50/50 with water, but how difficult is that? I use distilled water because my well water is kinda hard.

I'd use either one, as long as you don't go the whole 5 years like the silver bottle says. The silver bottle is DexCool, it can attack nylon 6-6 if you leave it in too long.

The only thing I'd worry about is rinsing the old stuff out real good. Certain combinations are really incompatible. I take out the thermostat, fill with water, run it for half a minute, & drain. Fill & drain a few more times until there's no more color when you drain. Then put in the thermostat & fill with new antifreeze.