You can install IOS80 without installing 4.3. It just doesn't do anything as it IS the 4.3 system menu and the boot process will call the last one it knows about.
If IOS80 is installed you should be able to use the DOP-Mii system update to reinstall 4.3. If Priiloader is installed next to IOS80 DOP-Mii will offer to back it up then restore it after everything is updated. I'm not sure if it recognizes Preloader, though.
so are you saying i can install Priiloader from dop-mii?
are you saying i should install IOS80 and possibly Priiloader at the same time?