I need to buy a set of race seats for my car but need the lowest possible arrangement for my 6'4" chassis. Best make and model?

I am 6'2" and have had good luck with the Kirkey seats. There's minimal structure (it's just an aluminum shell) and the padding is not too thick. Too gain extra space, I took out the sliders and mounted the seat directly to the floor using brackets.

The GT3 seat in Felixs car mounted really low. He might even be selling it.

get an FIA approved f/g shell seat with side mounts and bolt it to the floor
make sure you fit well in the seat you get
there's lots of brands/models to choose from