Don't know were you got that info, all the sportbikes are in the same range of seat height the GS500 31.1 inch the others within about a half inch of that ( usually half inch more ).
For specs click on the dirt bike on top of page and check out the bike by bike specs on home page.
BTW, seat height will tell you the distance from the seat to the ground but bike width will also affect your ability to put your feet flat on the ground and the seat height doesn't necessarily reflect the seat to peg distance so if leg room is your concern best thing to do is visit a dealer and try them on.