Hi Robbie
I sewed my own upholstery and used the confor foam pink over blue for the seat pan and blue for the backs. I used 1000D Cordura for the coverings which doesn't "give" much.
I tapered the foam towards the front under the legs.. its just the blue at the front. I even glued the under leg end foam on at an angle so they sit better on the pan. I made 4 individual cushions, 2 seat pans and 2 backs, all attached with Velcro.
Lots of work to sew though and a bit of head scratching to work out the how! I also fitted zippers.
After 40 hours of use I find them comfy on the seat bottom but not so much on the back. I was thinking of adding some conventional foam to increase the thickness on them, but might have to remake the back covers.
The other thing with them is they are pretty weighty due to the confor foam..
I have a couple of pics here:
( I remade the stick boots in a thinner vinyl and they sit a lot better than these..)
PS.. I cut the foam with a cheap electric meat carver. To get the taper I used a wooden jig to keep the blades at the correct cutting angle. Worked good!
Cheers
Tony