Variable wavelength IR Diode?
There are broadband IR LED's available that go from 650 to 1050nm

If I wanted two different IR wavelengths in one product, I would use two different SMT diodes with a light guide (make sure you check the tranmisitivity of the material of the light guide in the IR) 

Some of these light guides could probably fit two 0603's SMT LED's as they are