Depends on what your budget is....
If you're looking into Forged, the sky is the limit in regards to choices.
ADV.1, VIP Modular, Rennen, HRE/DPE, etc etc list goes on
For cast, your choices in 22 inch are quite limited. You can go with Beyern's like Nick mentioned.
My personal suggestion would be to check out the Forgestar F14. These are flow formed cast and a bit more expensive than regular cast...but they are lighter and stronger as well.
Here's a few pics, none I could find of these mounted on an X5 though.
