Quick Q re framing sliders

I have a one story ranch that I would like to add a second floor to... Hopefully. I am not sure I can due it due to bylaws and the fact that the house is on 10x10 poured concrete piers. My Q is not related to that though...

A couple of the concrete piers are roughly 8' OC. I am installing 2 - 8' sliders next to each other. I am using a 2x 8 header. I have a single jack stud, a king stud that goes up to the bottom of a single top plate, and then another Jack stud that sit right on top of the concrete piers. So, these 4.5" columns sit right on top of a concrete pier.

The Q is... Should I use a double King stud?

I had asked someone if I should double up the Jack studs and this person said... One Jack will prob take most of the load- unless they are really cut the exact same length.

If I put on a second story... I can add a second top plate. It is kind of funny, on the gable end of the house, there is a double top plat, on the sides of the house, there is a single top plate. It looks like the just forgot to put the second top plate. But if I take off the roof... I can add a second top plate on the side to match up the height of the gable end.

TIA !