Front seat question

How far the butt is off the floor is also important. Newer cars have the seat riser formed into their floor pan. Our old cars have similar risers for bench seat only. Risers for OEM buckets were incorporated in the tracks. Most modern buckets will likely need risers added under their flat seat tracks. Then that effects overall height. I think we have a high enough roof line that most any would fit even with 2 or 3 inch tall spacer underneath.
How and where they bolt down is a factor to consider also. The floor pan is weak. If your car had factory buckets you have extra plates welded in where those buckets were anchored.