In the photo your car appears sortof level. Today
I am replacing my moog cargo coils that have sagged to level status.
You are welcome to the old ones for the cost of shipping about $10.
Do you have Advance Auto Parts near you? In their computers are many selections for rear springs and one of the windows shows the specs with carring capacity, wire diameter, inner diameter, relaxed length, etc. Maybe other parts stores have this info in the computer.
Replacing the springs is very simple, remove the wheel remove the lower shock mount bolt/nut, let the axle sag, spring plops out. New spring requires additional sag from a helper stepping on the axle and in it goes, jack the axle back up and hook up shock. Same procedure on the other side.