large ellipsoid reflectors: Source?

Hello.

Do you know a source for "large ellipsoid reflectors" (To refer gladly in Germany)?
They should have more than 15.4" diameters. To 125% would be good. Those are 19.25 ". 17"to 19.25" would be also correct.

I found only a "Large Parabolic Reflector" (Edmund Optics). It has unfortunately a focus outside of the reflector.

A Cold Ellipsoidal Reflector would be good, but they have apparent a limited life span. That becomes in the long run too expensive.



Greetings,
Tobias Claren