When it comes to the audio world, it really seems like there are 3 options, Kinetik, Optima, Odyssey.

In the performance world, you basically want the smallest, lightest battery that is going to still have enough cranking amps to get things started.

What makes these batteries so much better than "normal" batteries?

Is it possible to run one of those tiny little batteries upfront and then one of these bigger batteries in the back?
I don't see any reason why you wouldn't just wire them in parallel.
Doing a little research, "they" say that you shouldn't mix the red top with the yellow top, IE run a red upfront and a yellow in the back unless they are wired totally seperate of each other. Something to do with the quick discharge of the red top not meshing well with the deep cycle of the yellow top.

How do you determine which battery is the best option?

I'm assuming it would be just fine to run two smaller, 800 amp batteries, in parallel, to give you a total of 1600 cranking amps, right? That's more than most normal batteries.