cushioning is not as important as having a seat whose shape fits your butt. Almost all of the pressure should be on your seat bones which should have good support from you seat. The cushion will be completely flattened where your seat bones are anyway. It's actually better to invest in a good pair of cycling shorts with a good chamois to keep your butt and crotch comfortable.

Seat height is also important. If the seat is too high, your pelvis will move back and forth as you ride, causing damage to your bits.