Android 2.2 (FroYo) firmwareEdit
Die Firmware Firmware v22.214.171.1242 Revision 1.0 - European Edition lässt sich problemlos auf dem meteorit MMB422 installieren.
Android 4.0.3 (ICS) firmwareEdit
Some users tried the Atlas 4.0.3 ICS firmware with succes. See  It's practically the same fw as the Pearl firmware, no usefull add-ons
Another user tried Himedia Q5 firmware on his Veolo without any succes.  That's due of the very different hardware of the Q5 and also a difference in NAND chunk and page sizes.
At this moment the Pearl FW seems the best choice for your MMB-422. A big disadvantage is the size of the data partition, it's not big enough to install e.g. XBMC or Chrome for Android.