decided to try my hand at shaping my own seat, integrating air bladder from airhawk seat cushion.
bought a used seat/saddle pan from e-bay for 50 dollars.
removed old cover and foam, cut bottom off old seat foam to fit in molded sections of seat pan.
bought some quality foam from foam shop in ashland, va, cost for foam was 40 dollars. nice chat with foam folks, every foam used in custom seats is available commercially, no magic/special/proprietary foam used by corbin, russell, et all so anyone with inclination can have a go.
after several attempts at cut, fit, shape, glue, etc i ended up with reasonable facsimile of a "custom" seat.
i set seat on frame and had a sit and fit several times to get the right shape. feels great and can't wait to get finished product and take a loooooooong ride.
I don't sew and this isn't the project to learn on so it's off to local upholstery shop for seat cover.
I'm in it for around 110 dollars counting seat pan, foam, batten fabric and adhesives.
will post final product and cost when i get seat back from upholsterer.