The proper forum for this question is parts & accessories.
What diameter is the seatpost? Is there a seatpost? If a 9/16" diameter seatpost at the top, then you have a choice of hundreds of other seats. cloud9 is one brand.
If the seat is supported by 2 horizontal rails about 5/16" diameter on a non-standard diameter shaft, as my yuba bike, you are limited to brooks seats and selle. As far as I know. My brooks seat was too narrow. I bought my selle royale respiro seat at modernbike.com. It looked good, but was too hard. I'm using a mesinger leather seat with 2 springs in the back, I found on a $15 bike at Salvation Army.