X-rays at various energies can be focussed with reflective optics at grazing incidence with a well-known reflectivity achieving a high effective area by means of various designs. On XMM the high collecting area was achieved by means of thin mirror shells which were made by nickel replication combining the parabola and hyperbola sections according to the WOLTER I design in a single element. 58 of these "elements" were combined to build a mirror assembly with an effective area of 1450 cm2 @1.5 keV per mirror assembly. In order to achieve a higher effective area for IXO the density needs to be reduced. This could be achieved by pore optics elements integrated into a set of 8 petals made of Cesic® as an optical bench. This design is fitting into the fairing of Ariane with a diameter of 4.2 m and achieves an effective area of 3.36 m2. It will withstand the high launch loads of up to 60 g and provide a negligible degradation to the optical performance due to thermal loads and gravitational relaxation. The design, including the interfaces to the telescope and to the pore optics, will be presented.