corsets! HELP!

Just doing a corset for a friend and I am thinking boning - she is VERY tall (well anybody taller than me is what i would call tall) and I hate really ridgid boning but will spiral wires be strong enough? will they kink? I will proably have to double up each line of boning to compensate for the longer line, but i still want it to be really comfy?

and what about spoon busks - stronger?