I can't edit my older post, so here is the updated list of the different seats and their descriptions based on what I found from various vendors when I looked them up:
Stock Hypermotard: no stitching
Race: Ducati logo embossed at the front, suede-like seating area - 96880082A
???: three lines across front and back, no stitching
Low: 20mm lower compared to standard seat, three lines across front and back, double row of red stitching - 96880072A
Journey: 20mm lower than standard seat, single row of red stitching, DP logo between rider and pillion areas - 59521572A - replaced by 96880062A
Stock Hyperstrada: single row of red stitching, "Hyperstrada" between rider and pillion areas, similar in appearance to the to Journey seat
I've decided I want a lower seat, but the descriptions for the Low and Journey seats both say they are lower than the stock seat (I assume Hypermotard) by 20mm. And since the Journey looks identical to my stock Hyperstrada seat, can I conclude that I have the lowest available seat already?