I kept 6 in a 20g long with pool filter sand, wood, rocks & plants. Some were always out, a couple liked floating Indian fern to lie in, 2 or 3 would hideunder the wood at any 1 time. I kept threadfin rainbows & CPDs (celestial pearl danios) with them. I now have them with red cherry shrimp, otos, black kuhlis & some other small loaches in a 40g long.
Kuhlis aren't fussy eaters, I feed a wide variety of foods: flake, sinking pellets, microwafers, frozen bloodworms, daphnia & cyclops. Mine don't seem to eat veggies although will eat algae wafers & veggies pellets.
Here's a good article
http://www.loaches.com/species-index/pangio-kuhlii
I don't know where to get them but if you can wait a week or 2 after the lfs gets them you'll have better luck, they often don't ship well. The black seem a bit hardier & more active for me.