A huge thanks to Hennesie2000 and ProfDrLuigi and everyone making this work
I followed the step by step tutorial by Hennesie2000 and did a clean install on my old MP 1.1 flashed to 2.1 on a SSD and it all went great.
Only problem was the graphic didn't work with my flashed Radeon HD 4890, but now i just used the qeci1010 provided by ProfDrLuigi with Kext Drop, rebooted and wohoo... graphic working fine.
The computer also feels snappier than with 10.7, booting fast with boot screen and all
Messages doesn't work as like others have mentioned but that's something i can live with until a fix for that is found.
I'm so grateful and happy i can still use my old MP1.1 now with Yosemite since i was previous stuck on 10.7.4 and things just kept getting more complicated when programs demanded being upgraded but didn't support 10.7.
So again.. Thank you everyone for this