These would be the strongest and safest you could get. I've seen them nicely upholstered too which turns them from a race seat into something nice and comfortable. I'm not sure whether you could fit a headrest, if that's something you'd want to do.
https://www.kirkeyracing.com/product...E-CLASS-BUCKET
Available from
https://www.ianboettcherraceparts.co.../Kirkey-Seats/