We are back and the answers are coming.
Pexi: Oli did a good job so far. The Ninja PLUS Rev. A is compatible to socket 775, but you need to have the supplied backplate mechanism, which was with it. Do you still have it? If yes, then there is no need in buying the Universal Retention Kit, because it is the same thing that you have with your Ninja. I don't have the mobo here, but based on the images I found, there should be no problems with the Abit IP35 Pro. The heatsink seems to be not that tall and it is in safe distance.
Oli: Thanks!
Els: Ok, thanks for confirming. I will add it to the list. I hope you'll enjoy the silence
Child: Thanks for the conformation! I will add it to the list right away. As for the Retention Kit, it is not a must, you can also mount the Heatsink w/o the copper spacer