Choice of handguards will be determined by what type of riding/racing you do.
The handguards that connect into the ends of the bars are illegal for use in MX. If your racing MX, then you have to use the open end, mx style guards.
Tyring moving the levers in, so that the end of the lever is not even or extends past the end of the handle bars or use the shorter levels from ASV or Moose.
If your just play riding or doing off road, then use the ones that wrap around and connect into the ends of the handle bar. I believe the Acerbis ones are the least expensive.
We use the Cycra ProBends guards on my sons offroad bike.