The nand is still there is some form. Probably the info on nand that tracks the installed titles has become corrupt, so when you boot no ios is found. I have no idea why bootmii is not loading, but possibly your boot2 is as partially corrupted. I don't think there is anything else you can do for it. There is some major failure on the wii's nand. You could send it to someone who specializes in wii hardware to work on it further if you like. I would either get a new wii, or send it to Krafter and have him figure it out.
Edit- Why don't you try to nand formater one more time, with only the system ios60 and the system menu 4.1 wads.