I've been using an Legacyfirearmsco Cronus with my ECE. If going that route, just get the DCC belt clip and modwing right off the bat. They are the better options. As for other companies, I'm not fully awake and can't remember who else makes one for the combat. I know Teir 1 doesn't unfortunately. Nor Wee The People if i remember correctly.
Sorry, not much help but hopefully it's a start.