So what would be a good optic to put on a HK UMP clone? My USC is on it's way to HDPS for the conversion right now & I would like to get something before it gets back. I've been looking at the EOTech XPS3-0 or 3-3. It's a lot smaller then the regular EOTechs. I can't find anything by Trijicon that would really work. I'm just curious to see what someone else uses on their UMPs. Thanks for any advise.