If you choose kuhli loaches don't add them until the tank has been restocked. They need well established tanks, hiding spots and substrate that isn't sharp. Don't forget to buy a quality heater since you're converting from a cold water to a tropical fish. Don't buy a cheap brand since they are more prone to failure. I also agree with adding the fish a few at a time since your tank probably isn't totally cycled anymore. The sooner you start adding fish the better.