cant get it though
also you want to be at 4.1 or 4.2(no furhter advantage to 4.1, same with 4.3) in my opinion.
I know you want your clean nand backup, but for every other thing there are tools such as dopmii
to correct stuff with IOS, like getting a new version, unpatch/patch etc. (don't install stubs).
Softmod ANY Wii
would be the one to go for to have it step by step and doing the nand backup as mentioned there.
also there is no need to get rid of bootmii or priiloader or so. would even update to latest versions. then do the backup, then ran over a softmod guide ending up with good cios set etc.