Bought airtex and am very pleased with results. Didn't do cut out after much investigation. Be ready to do more work when you pull seats out. If you pull a floor panel you may find 50 years worth of dirt and grime, decayed insulation and, in my case..an old rat trap. Fortunately it was empty.
My carpet is out every year. I want to look under the floorboards! After finding cracks it the bulkheads under the seat rails in multiple Comanches the floorboards will probably start coming out too!