IMO, the best dither for any loaches is Asian Cyprinids. Best to choose from small Danios or Rasboras. White Clouds are also OK. Barbs are generally worse, but very small ones (e.g. Cherry) is OK. It is better to chose less active dither, it will stress kuhlis less.
My personal favorite for quiet dither is Blackline Rasbora (aka Redtail Rasbora, aka Brilliant Rasbora): these are reasonably attractive, quite and hardy 2" fishes.
Microrasboras should work nicely too.
And, of course, sand, some driftwood and plants, for best results.
hth