At a minimum the one with rebound and preload. Basically:
Cheapest - just preload
Middle priced - preload and rebound
Expensive - preload, rebound and compression
The most expensive - preload, rebound, fast and slow compression
It will tell you on any adverts which one it is.
You can look on the YSS website, or call them. If you go to their service center in Bangkok, they will install and set it up for you, just book an appointment first. If you don't live in Bangkok, ask YSS to tell you the best dealer in your area, who will install and do the set up for you.