I have no experience with the fish you're suggesting as tankmates (I'm a tetra person myself), but I have always been happy with cories as terrific members of a community tank.
They come in many different varieties and sizes - and one thing they are not is shy! Mine scoot around the tank all day, and often play with the other fish as well as each other.
All other bottom feeders I've ever had (loaches, otos, and plecos) were pretty shy and/or nocturnal.