I’ve been planning since my purchase to replace/recover my seats mostly because the previous owner clearly had a large clawed dog. Small holes and now some failing seat back stitching. I’ve got the black leather (perforated inserts) and I prefer leather. I know that at www.LSeat.com one can purchase seemingly identical covers decent quality replacement covers for $340. I would like to add heated seat pads and would like to increase the bolstering (within reason). I am starting a thread here to see what products (brands), ideas, improvements, warnings, you have. I have geared my car to be more a playful touring versus stripped autoX.
When I had a set rebuilt for my Model A I had them remove some of the seat base cushion and back cushion to replace it with memory foam and increase the bolstering. A good shop will leave it up to your wishes and budget.
I went with memory foam since it was a Model A and they weren't really known for their soft ride.
Different types and density of foam for the bolstering was offered as well. Seats are like custom paint. It is easy to lose your damn mind and run the price up. With the Spyder there are off the shelf options which is what I ended up going with versus doing anything custom. For the price of building custom seats you can buy some really nice quality aftermarket stuff.