Looking at the specs and photos, it appears that the Ehiem and Danner may be the same pump.
I ended up with a Rio 800 commonly available at your local aquarium store for $25. I got the idea from the wimpy Rio 90 Leufkens sells. The Rio 90 is only rated at 54 gallons per hour with one foot of lift. It’s not even rated for two feet of lift. It definitely would not work in my system as Leufkens’ claimed it would. The Rio 800 is rated at 133 gallons per hour with two feet of lift. The Rio 800 is idealy suited to the two feet of lift in my system and the multiple 180 degree bends in the Danger Den water block and Cooling Cube. I simply epoxied the pump to a plastic electrical junction box, mimicking the Leufkens design with far more structural integrity and no chance of any aluminum reacting with the copper in the system. The only draw back to this is the pump resonates through the reservoir and is a bit too loud, even when mounted on foam weather stripping. I expect I will eventually switch to a separate pump and reservoir. In the meantime, I’m happy and my Bird is nice and frosty.