this cover is amazing it keeps you on the seat in the position you want to be in the ridges let you know when to move forward or backwards when needed the look and quality is second to none the shipping with motosport has always been great as well i have never had any problems or arguments due to not having parts in time for races my backgrounds are the only part on my bike that didnt come from motosport
Any of the aftermarket seat covers are going to be made of a gripper type material which may not do any better than the stock seat cover in your situation. I suggest maybe using some knee guards and long socks to aid in preventing this from happening.
The best way i've found to install a seat cover is to let let it sit by a heater for an hour or two. This way it streches easier. Then strech it over the seat foam and use a staple gun(electric gun works the best) and go all the way around the edge of the cover....staple to the plastic shell.
it does not come with staples i bought ones at sears that were just about the same size..pull out the old staples put cover over front of the seat staple it pull it tight staple the back then staple the rest as you go making sure you have no wrinkles its a simple job
It's going to be a tight squeeze but I'm sure you can make it work, the only thing I would be worried about would be the extra height with the bump built into the cover so you might need to shave the foam down on the seat where the step on the cover would sit.