Install newest ROM on Huawei Ascend G700

I want to install a new, clean OS on my Android phone. My phone is a Huawei Ascend G700, the specs are here -> Offical Huawei specs

Where can I find the ROM for this phone? The only ROM's I see are for the more "known" phones, like Nexus, or Samsung.

I would prefer to download the newest version of Android, KitKat or Lollipop. Now I have the 4.2.1 Android version.

If it is not possible to install the newest version, I want to download the clean version of 4.2.1. Does somebody know where to download this?

Thanks in advange!