We tried several seat pads:
1) Sheepskin -- $60; keeps you dry, but it does nothing to soften the pressure on the ischium bones, which is a ride-ender;
2) Wooden Bead Seat Cover -- $40; plenty of air flow, works better than most, but the ischium bones still begin to hurt after a few days of 6+ hours on the bike;
3) AirHawk M/C Pad -- $90, used; could not get this to work, period; tried repeatedly, varied the amount of air, ad nauseum, just couldn't make it work;
4)
Gypsy Quilter Sit Upon -- $35 at
JoAnn's Fabric Store; Hallelujah, Baby! Best money ever spent, period! Comes pre-filled with the correct amount of air -- has fill valve, same as a basketball/football; takes a little getting used to, as you tend to shift a bit, in turns, but it beats everything else we tried; we can ride around two more days than we could with the Wooden Beads; puts the least amount of pressure on the ischium bones, but eventually, you will hurt, and be forced to get off the bike; incredibly effective, and affordable. Highly recommended. If you don't like the purple color, sew a black bag/case for it. Cheers!