Hi guys,
So, I followed BoomR's guide and got very similar Hardware. I encountered a few issues at the installation and post install.
1. UniBeast Install had me wait for a Server reply after clicking the Install Mac OS Button. Fixed that in the terminal of the booted Installation.
2. Black screen after the first installation. My system is very quite, and I heard that some fan noise changed right before the black screen. The fans of the GFX card reduced their rotational speed. I suspected that there is some issues with the graphic driver, so I googled and found that getting Lilu and whatevergreen.kext onto the UniBeast stick would help. And voila, I could finally boot into the OS.
3. Bluetooth Magic Keyboard issue. Sadly the IOGEAR GBU521W6 doesn't work in the BIOS or POST for HID commands, luckily for Clover Bootselection I can use a Logitech cordless mouse with a proprietary dongle
4. LEDs are on in Sleep/off status
5. No Audio over HDMI
Hope the hint with the kext is helping...