I checked and my PS3 is one of the one’s that is said to work with Waninkoko’s CFW. I checked the model number.. I have the 320 GB slim move pack.
And I could be wrong but from what I understand the FAT ps3’s have a larger nand than the slim ps3’s. I believe it is because they were built to support hardware emulation for ps2 games, where as the slim is not.